Architecture for differential drive and sense for touch sensor panel

ABSTRACT

Differential driving and/or differential sensing can reduce noise in the touch and/or display systems of a touch screen. In some examples, the touch sensor panel can include column and row electrodes routed vertically to a first edge of the touch sensor panel. In some examples, a touch sensor panel can be divided into banks. In some examples, the routing traces for rows can be implemented using four routing tracks per column for three banks. In some examples, the arrangement of routing traces within routing tracks can improve optical characteristics and/or reduce routing trace resistances and loading. In some examples, interconnections between routing traces and row electrodes can have a chevron pattern, an S-shape pattern, or a hybrid pattern. In some examples, differential sense routing can reduce cross-coupling within the touch sensor panel. In some examples, staggering differential drive signals can reduce parasitic signal loss.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.63/261,624, filed Sep. 24, 2021, the content of which is incorporatedherein by reference in its entirety for all purposes.

FIELD OF THE DISCLOSURE

This relates generally to touch sensor panels/screens, and moreparticularly to touch sensor panels/screens with differential driveand/or sense.

BACKGROUND OF THE DISCLOSURE

Many types of input devices are presently available for performingoperations in a computing system, such as buttons or keys, mice,trackballs, joysticks, touch sensor panels, touch screens and the like.Touch screens, in particular, are popular because of their ease andversatility of operation as well as their declining price. Touch screenscan include a touch sensor panel, which can be a clear panel with atouch-sensitive surface, and a display device such as a liquid crystaldisplay (LCD), light emitting diode (LED) display or organic lightemitting diode (OLED) display that can be positioned partially or fullybehind the panel so that the touch-sensitive surface can cover at leasta portion of the viewable area of the display device. Touch screens canallow a user to perform various functions by touching the touch sensorpanel using a finger, stylus or other object at a location oftendictated by a user interface (UI) being displayed by the display device.In general, touch screens can recognize a touch and the position of thetouch on the touch sensor panel, and the computing system can theninterpret the touch in accordance with the display appearing at the timeof the touch, and thereafter can perform one or more actions based onthe touch. In the case of some touch sensing systems, a physical touchon the display is not needed to detect a touch. For example, in somecapacitive-type touch sensing systems, fringing electrical fields usedto detect touch can extend beyond the surface of the display, andobjects approaching near the surface may be detected near the surfacewithout actually touching the surface.

Capacitive touch sensor panels can be formed by a matrix of partially orfully transparent or non-transparent conductive plates (e.g., touchelectrodes) made of materials such as Indium Tin Oxide (ITO). In someexamples, the conductive plates can be formed from other materialsincluding conductive polymers, metal mesh, graphene, nanowires (e.g.,silver nanowires) or nanotubes (e.g., carbon nanotubes). It is due inpart to their substantial transparency that some capacitive touch sensorpanels can be overlaid on a display to form a touch screen, as describedabove. Some touch screens can be formed by at least partiallyintegrating touch sensing circuitry into a display pixel stack-up (i.e.,the stacked material layers forming the display pixels).

SUMMARY OF THE DISCLOSURE

This relates to touch sensor panels (or touch screens or touch-sensitivesurfaces) with improved signal-to-noise ratio (SNR). In some examples, atouch sensor panel can include a two-dimensional array of touch nodesformed from a plurality of touch electrodes. For example, thetwo-dimensional array of touch nodes can be arranged in rows andcolumns. Each column (or row) of touch nodes can be driven with aplurality of drive signals. For example, a first drive signal can beapplied to first column electrodes within a column of touch nodes and asecond drive signal can be applied to second column electrode with thecolumn of touch nodes. Each row (or column) of touch nodes can be sensedby sense circuitry (e.g., differentially). For example, a first rowelectrode within a row of touch nodes can be coupled to a first inputand a second row electrode within the row of touch nodes can be coupledto a second input, such that a first input and second input can bedifferentially sensed. Differential driving (e.g., using complementarydrive signals) and/or differential sensing can reduce noise in the touchand/or display systems of the touch screen.

The column electrodes can be routed vertically (e.g., overlapping thetwo-dimensional array of touch nodes) to a first edge of the touchsensor panel to couple the column electrodes to drive circuitry. In someexamples, row electrodes can be routed from a second edge of the touchsensor panel (e.g., perpendicular to the first edge) in a border regionaround the two-dimensional array of touch nodes. In some examples, therow electrodes can also be routed vertically (e.g., overlapping thetwo-dimensional array of touch nodes) to the first edge of the touchsensor panel. In some examples, the routing traces can be formed frommetal mesh.

In some examples, a touch sensor panel can be divided into three banksof rows (e.g., more generally for a plurality of banks of rows). In someexamples, the routing traces for rows can be implemented using fourrouting tracks (also referred to herein as a set of one or more routingtrace segments) per column for the three banks. In some examples, toimprove optical characteristics (e.g., reduce visibility of the metalmesh), the four routing tracks can extend the vertical length of thetouch sensor panel (e.g., the length of the column of touch nodes). Insome examples, routing traces implemented in the four routing tracesusing electrical connections and/or discontinuities within the routingtracks can be used to improve characteristics of the routing. Forexample, a discontinuity in a routing track after an electricalconnection to a row electrode can reduce the capacitive loading of arouting trace to the row electrode. The discontinuity can also allow forother routing trace segments within the routing track to be used foranother routing trace to reduce the resistance of the routing trace. Insome examples, the utilization of the routing tracks for routing tracescan be optimized to reduce routing trace resistances.

In some examples, the interconnections between routing traces and rowelectrodes can have a chevron pattern to reduce maximum routing traceresistance and/or to balance routing trace resistance across the touchsensor panel. In some examples, the interconnections between routingtraces and row electrodes can have an S-shape pattern (also referred toas diagonal or zigzag) to reduce row-to-row differences in resistance(and reduce discontinuities in bandwidth for the touch sensor panel). Insome examples, the interconnections between routing traces and rowelectrodes can have a hybrid pattern, in which upper and lower rows canhave the diagonal pattern similar to the S-shape pattern, andintermediate rows can have border area routing outside of the area ofthe two-dimensional array of touch nodes. The hybrid pattern can providefor increased usage of routing tracks for longer routing traces (e.g.,most distant from the sensing circuitry).

In some examples, differential sense routing can be implemented toreduce cross-coupling within the touch sensor panel. For example, therouting traces for row electrodes that are used for a differentialmeasurement can be routed in pairs such that cross-coupling becomescommon mode and cancels out in the differential measurement. In someexamples, staggering the differential drive signals and reduce parasiticsignal loss for a differential drive and sense measurement. For example,rather than applying complimentary drive signals to different touchnodes within a column, complimentary drive signals can be applied in anadjacent column. In some examples, the complimentary drive signals canbe applied to diagonally adjacent touch nodes.

In some examples, routing traces for a touch sensor panel can beimplemented in an active area (at least partially). In some examples,the touch electrodes and routing traces can be implemented using metalmesh in a first metal layer and using bridges in a second metal layer tointerconnect conductive segments of the metal mesh forming the touchelectrodes. In some examples, the touch electrodes can be implementedusing metal mesh in a first metal layer and using bridges in a secondmetal layer to interconnect conductive segments of the metal meshforming the touch electrodes, and the routing traces can be implementedusing metal mesh in the first metal layer and using metal mesh in thesecond metal layer. In some examples, the touch electrodes and/orrouting traces can be implemented using metal mesh in a first metallayer and using metal mesh in a second metal layer.

In some examples, portions of metal mesh for a touch electrode and/orrouting trace overlapping and in parallel between the first metal layerand the second metal layer. In some examples, to improve opticalperformance, the overlapping, parallel portions can be aligned. In someexamples, to improve optical performance, the width of the metal mesh inthe first layer can be greater than the width of the metal mesh in thesecond layer for the overlapping, parallel portions. In some examples,to improve optical performance, the metal mesh in the first metal layerand the metal mesh in the second metal layer for a touch electrode canbe non-parallel (e.g., orthogonal), such that overlapping portions canhave a substantially uniform area across the touch electrode (e.g.,within a threshold such as 2 microns-squared or 1.5 microns-squared).

In some examples, to improve SNR and touch sensor panel bandwidth, adielectric layer between the first metal layer and the second metallayer can reduce capacitive coupling therebetween (e.g., parallel platecapacitance). For example, the dielectric layer can have an increasedthickness and/or a reduced dielectric constant to reduce the capacitivecoupling. In some examples, to improve SNR and touch sensor panelbandwidth, the metal mesh in the first metal layer can be flooded,filled or otherwise augmented with a transparent conductive materialelectrically coupled to the metal mesh (optionally separated from thefirst metal layer by a dielectric layer).

In some examples, to reduce cross-talk in a non-differential operatingmode (e.g., stylus or self-capacitance), routing traces can be disposedin a second metal layer beneath touch electrodes implemented in thefirst metal layer (and optionally also in the second metal layer). Insome examples, to reduce cross-talk in a non-differential operating modeand to improve SNR and touch sensor panel bandwidth, the metal mesh fortouch electrodes in the first metal layer can be flooded, filled orotherwise augmented with a transparent conductive material electricallycoupled to the metal mesh, without flooding, filling or otherwiseaugmenting the metal mesh for routing in the first metal layer with thetransparent conductive material.

In some examples, a stack-up of a display and touch sensor can includeat least one encapsulation layer, over which components of the stack-upare disposed or otherwise formed. Display components formed on asubstrate can be covered by a first encapsulation layer formed usingeither a selective or blanket deposition method (e.g., using an ink-jetprinting process). A display-noise shield or sensor can be formed on thefirst encapsulation layer using an on-cell process. In some examples,the use of the on-cell process can improve alignment of structures ofthe shield or sensor to the display components (and thereby can improvemanufacturing yield for the stack-up).

In some examples, a display-noise sensor can detect signalscorresponding to electrical interference from the display components. Insuch examples, the display-noise sensor can include one or more metallayers that can be patterned such that rows and columns of display-noisesensor electrodes are substantially aligned with rows and columns of thedisplay components. During readout of touch signals at a touch screenformed over the display components, display-noise sensor signals of thedisplay-noise sensor can simultaneously read out and subtracted from thetouch signals to reduce or remove electrical interference of the displayfrom the touch signals.

In some examples, a display-noise shield can mitigate signalscorresponding to electrical interference from the display componentsfrom passing through the stack-up to the touch sensor. In such examples,the display-noise shield can be a layer of metal mesh formed across allthe display components (e.g., a global mesh structure). In otherexamples, the display-noise shield can be a flood of solid transparentconductive material formed across all the display components (e.g., aglobal fill, or solid metal layer structure). In further examples, thedisplay-noise shield can be a combination layer of metal mesh and solidtransparent conductive material, together formed across all the displaycomponents (e.g., alternating sections of metal mesh and/or patches ofthe transparent conductive material).

In some examples, a second encapsulation layer can be formed over thedisplay-noise shield/sensor. In some examples, a dielectric layer can beformed over the second encapsulation layer to mitigate the impact of anyparasitic capacitances between the shield/sensor and a touch screen inthe stack-up. The second encapsulation layer can be formed using anink-jet printing deposition process. A touch sensor can be formed abovethe second encapsulation layer, according to an on-cell manufacturingprocess (e.g., to improve alignment and/or avoid a lamination of adiscrete touch sensor to a display stack-up).

In some examples, readout circuitry can be configured to simultaneouslyread out touch signals from the touch sensor and signals from thedisplay-noise sensor to produce a noise-corrected touch signal (e.g., toreduce or eliminate electrical interference caused by the display). Insome examples, a display-noise shield can be biased to a fixed voltagelevel (e.g., a ground voltage level, or a non-zero voltage level).

In some examples, a touch electrode architecture for differential drivewithout differential sense can be implemented. Differential drive canstill reduce the touch-to-display noise. The touch electrodearchitecture for differential drive can simplify the touch electrodearchitecture design because fewer routing traces and fewer bridges arerequired compared with some of the differential drive and differentialsense touch electrode architectures described herein.

In some examples, one or more touch nodes in a touch electrodearchitecture each include a differential pair of row electrodes and adifferential pair of column electrodes. For example, a touch node caninclude a portion of first row electrode Rx0+ and a portion of a secondrow electrode Rx0− (e.g., corresponding to differential inputs for touchsensing), and a portion of a first column electrode Tx0+ and a portionof a second column electrode Tx0− (e.g., corresponding to differential,complimentary outputs of touch driving). The arrangement of the firstand second row electrodes and the first and second column electrodes canresult in two dominant mutual capacitances that are in-phase.Additionally, because the touch node includes portions of the first andsecond row electrodes and the first and second column electrodes, thedifferential cancelation occurs on a per touch node basis rather thanacross two touch nodes. Additionally, the non-dominant (minor) parasiticcapacitance can be reduced by reducing routing lengths and increasingseparation between electrodes that generate parasitic mutualcapacitances.

In some examples, the touch electrode architecture includes fullydifferentially interleaved row and column electrodes within a touchnode. In some examples, the touch electrode architecture differentialfor row (or column) electrodes and pseudodifferential for column (orrow) electrodes.

In some examples, common mode noise can be reduced using spatialseparation and spatial filtering. The spatial separation between touchsignal and common mode noise signal can be achieved using a touchelectrode architecture with reduced pitch for the transmitter andreceiver electrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1E illustrate example systems that can include a touch screenaccording to examples of the disclosure.

FIG. 2 illustrates an example computing system including a touch screenaccording to examples of the disclosure.

FIG. 3A illustrates an exemplary touch sensor circuit corresponding to aself-capacitance measurement of a touch node electrode and sensingcircuit according to examples of the disclosure.

FIG. 3B illustrates an exemplary touch sensor circuit corresponding to amutual-capacitance drive line and sense line and sensing circuitaccording to examples of the disclosure.

FIG. 4A illustrates touch screen with touch electrodes arranged in rowsand columns according to examples of the disclosure.

FIG. 4B illustrates touch screen with touch node electrodes arranged ina pixelated touch node electrode configuration according to examples ofthe disclosure.

FIG. 5 illustrates an example touch screen stack-up including a metalmesh layer according to examples of the disclosure.

FIG. 6A illustrates a symbolic representation of a touch sensor panelimplementing differential sensing according to examples of thedisclosure.

FIG. 6B illustrates a symbolic representation of a touch sensor panelimplementing differential driving and differential sensing according toexamples of the disclosure.

FIG. 7A illustrates a portion of a touch sensor panel that can be usedto implementing differential driving and/or differential sensingaccording to examples of the disclosure.

FIGS. 7B-7C illustrate different configurations of routing traces for atouch node with two vertical routing traces for row electrodes and fourvertical routing traces for column electrodes according to examples ofthe disclosure.

FIGS. 8-10 illustrate different routing patterns for row electrodesaccording to examples of the disclosure.

FIGS. 11A-11B illustrate an example touch sensor with vertical routingtraces and corresponding signal levels with and without cross-talkaccording to examples of the disclosure.

FIGS. 11C-11D illustrate portions of example touch sensor panels withnon-differential routing traces or with differential routing tracesaccording to examples of the disclosure.

FIGS. 12A-12B illustrate an example touch node in a row-columnarchitecture using single-ended capacitance measurements or differentialcapacitance measurements according to examples of the disclosure.

FIGS. 13A-13B illustrate portions of touch sensor panels andrepresentations of stimulation applied the touch sensor panels accordingto examples of the disclosure.

FIGS. 14A-14B illustrate a two-layer configuration including touchelectrodes and routing traces in a first layer and bridges in a secondlayer according to examples of the disclosure.

FIGS. 14A and 14C illustrate a two-layer configuration including touchelectrodes and routing traces in a first layer and bridges and stackedrouting traces in a second layer according to examples of thedisclosure.

FIGS. 15A-15B illustrate partial views of the two-layer configuration ofFIGS. 14A-14C according to examples of the disclosure.

FIG. 16 illustrates a partial view of the two-layer configurationincluding stacked touch electrode segments in the first layer and thesecond layer, a routing trace in the first layer and stacked routingtrace segments in the second layer according to examples of thedisclosure.

FIGS. 17A-17D illustrate cross-sectional views of a portion of exampletwo-layer configurations according to examples of the disclosure.

FIG. 18 illustrates a portion of a two-layer configuration including atouch electrode implemented partially in a first layer and partially ina second layer according to examples of the disclosure.

FIG. 19A illustrates a partial view of a two-layer configurationincluding stacked touch electrode segments in the first layer and thesecond layer and stacked routing traces in the first layer and thesecond layer according to examples of the disclosure.

FIG. 19B illustrates a partial view of a two-layer configurationincluding stacked touch electrode segments in the first layer and thesecond layer and a buried routing trace in the second layer according toexamples of the disclosure.

FIG. 19C illustrates a partial view of a two-layer configurationincluding stacked touch electrode segments in the first layer and thesecond layer and a buried routing trace in the second layer according toexamples of the disclosure.

FIG. 20A illustrates a partial view of a two-layer configurationincluding stacked touch electrode segments in the first layer and thesecond layer and stacked routing traces in the first layer and thesecond layer according to examples of the disclosure.

FIGS. 20B-20C illustrate example cross-sectional views of a portion ofthe two-layer configuration including a transparent conductive materialflood according to examples of the disclosure.

FIG. 21 illustrates a partial view of a two-layer configurationincluding stacked touch electrode segments in the first layer and thesecond layer and stacked routing traces in the first layer and thesecond layer according to examples of the disclosure.

FIG. 22 illustrates an example touch screen stack-up including anencapsulation layer and optional dielectric layer for isolationaccording to examples of the disclosure.

FIG. 23 illustrates example layers of a display-noise sensor formed on aprinted layer of a touch screen stack-up according to examples of thedisclosure.

FIG. 24 illustrates an example display-noise shield formed on a printedlayer of a touch screen stack-up according to examples of thedisclosure.

FIG. 25 illustrates an example touch sensor of a touch screen stack-upaccording to examples of the disclosure.

FIG. 26 illustrates an example transfer-type touch sensor of a touchscreen stack-up according to examples of the disclosure.

FIG. 27 illustrates exemplary readout terminals of a touch sensor and apixel-aligned display-noise sensor of a touch screen stack-up accordingto examples of the disclosure.

FIG. 28 illustrates exemplary readout terminals of a touch sensor and adisplay-noise shield of a touch screen stack-up according to examples ofthe disclosure.

FIG. 29 illustrates exemplary readout circuitry for a touch sensor and adisplay-noise sensor of a touch screen stack-up according to examples ofthe disclosure.

FIG. 30 illustrates an exemplary voltage bias for a display-noise shieldof a touch screen stack-up according to examples of the disclosure.

FIG. 31 illustrates an example process for operating a touch screenstack-up with a touch sensor and a display-noise sensor between thetouch sensor and display pixels according to examples of the disclosure.

FIG. 32 illustrates an example process for forming a touch screenstack-up with a display-noise shield/sensor formed on a first printedlayer and a touch sensor formed on a second printed layer according toexamples of the disclosure.

FIG. 33 illustrates a portion of an example touch sensor panel accordingto examples of the disclosure.

FIG. 34 illustrates a portion of an example touch sensor panelconfigured for differential drive according to examples of thedisclosure.

FIGS. 35A-35B illustrate example touch electrode architectures accordingto examples of the disclosure.

FIG. 36 illustrates an example touch electrode architecture that isfully differential within a touch node according to examples of thedisclosure.

FIG. 37 illustrates a portion of an example touch sensor panelconfigured for differential drive according to examples of thedisclosure.

FIG. 38 illustrates a portion of an example touch sensor panelconfigured for differential drive according to examples of thedisclosure.

FIG. 39 illustrates plots of spatial touch signal and noise according toexamples of the disclosure.

DETAILED DESCRIPTION

In the following description of examples, reference is made to theaccompanying drawings which form a part hereof, and in which it is shownby way of illustration specific examples that can be practiced. It is tobe understood that other examples can be used and structural changes canbe made without departing from the scope of the disclosed examples.

This relates to touch sensor panels (or touch screens or touch-sensitivesurfaces) with improved signal-to-noise ratio (SNR). In some examples, atouch sensor panel can include a two-dimensional array of touch nodesformed from a plurality of touch electrodes. For example, thetwo-dimensional array of touch nodes can be arranged in rows andcolumns. Each column (or row) of touch nodes can be driven with aplurality of drive signals. For example, a first drive signal can beapplied to first column electrodes within a column of touch nodes and asecond drive signal can be applied to second column electrode with thecolumn of touch nodes. Each row (or column) of touch nodes can be sensedby sense circuitry (e.g., differentially). For example, a first rowelectrode within a row of touch nodes can be coupled to a first inputand a second row electrode within the row of touch nodes can be coupledto a second input, such that a first input and second input can bedifferentially sensed. Differential driving (e.g., using complementarydrive signals) and/or differential sensing can reduce noise in the touchand/or display systems of the touch screen.

The column electrodes can be routed vertically (e.g., overlapping thetwo-dimensional array of touch nodes) to a first edge of the touchsensor panel to couple the column electrodes to drive circuitry. In someexamples, row electrodes can be routed from a second edge of the touchsensor panel (e.g., perpendicular to the first edge) in a border regionaround the two-dimensional array of touch nodes. In some examples, therow electrodes can also be routed vertically (e.g., overlapping thetwo-dimensional array of touch nodes) to the first edge of the touchsensor panel. In some examples, the routing traces can be formed frommetal mesh.

In some examples, a touch sensor panel can be divided into three banksof rows (e.g., more generally for a plurality of banks of rows). In someexamples, the routing traces for rows can be implemented using fourrouting tracks (also referred to herein as a set of one or more routingtrace segments) per column for the three banks. In some examples, toimprove optical characteristics (e.g., reduce visibility of the metalmesh), the four routing tracks can extend the vertical length of thetouch sensor panel (e.g., the length of the column of touch nodes). Insome examples, routing traces implemented in the four routing tracesusing electrical connections and/or discontinuities within the routingtracks can be used to improve characteristics of the routing. Forexample, a discontinuity in a routing track after an electricalconnection to a row electrode can reduce the capacitive loading of arouting trace to the row electrode. The discontinuity can also allow forother routing trace segments within the routing track to be used foranother routing trace to reduce the resistance of the routing trace. Insome examples, the utilization of the routing tracks for routing tracescan be optimized to reduce routing trace resistances.

In some examples, the interconnections between routing traces and rowelectrodes can have a chevron pattern to reduce maximum routing traceresistance and/or to balance routing trace resistance across the touchsensor panel. In some examples, the interconnections between routingtraces and row electrodes can have an S-shape pattern (also referred toas diagonal or zigzag) to reduce row-to-row differences in resistance(and reduce discontinuities in bandwidth for the touch sensor panel). Insome examples, the interconnections between routing traces and rowelectrodes can have a hybrid pattern, in which upper and lower rows canhave the diagonal pattern similar to the S-shape pattern, andintermediate rows can have border area routing outside of the area ofthe two-dimensional array of touch nodes. The hybrid pattern can providefor increased usage of routing tracks for longer routing traces (e.g.,most distant from the sensing circuitry).

In some examples, differential sense routing can be implemented toreduce cross-coupling within the touch sensor panel. For example, therouting traces for row electrodes that are used for a differentialmeasurement can be routed in pairs such that cross-coupling becomescommon mode and cancels out in the differential measurement. In someexamples, staggering the differential drive signals and reduce parasiticsignal loss for a differential drive and sense measurement. For example,rather than applying complimentary drive signals to different touchnodes within a column, complimentary drive signals can be applied in anadjacent column. In some examples, the complimentary drive signals canbe applied to diagonally adjacent touch nodes.

In some examples, routing traces for a touch sensor panel can beimplemented in an active area (at least partially). In some examples,the touch electrodes and routing traces can be implemented using metalmesh in a first metal layer and using bridges in a second metal layer tointerconnect conductive segments of the metal mesh forming the touchelectrodes. In some examples, the touch electrodes can be implementedusing metal mesh in a first metal layer and using bridges in a secondmetal layer to interconnect conductive segments of the metal meshforming the touch electrodes, and the routing traces can be implementedusing metal mesh in the first metal layer and using metal mesh in thesecond metal layer. In some examples, the touch electrodes and/orrouting traces can be implemented using metal mesh in a first metallayer and using metal mesh in a second metal layer.

In some examples, portions of metal mesh for a touch electrode and/orrouting trace overlapping and in parallel between the first metal layerand the second metal layer. In some examples, to improve opticalperformance, the overlapping, parallel portions can be aligned. In someexamples, to improve optical performance, the width of the metal mesh inthe first layer can be greater than the width of the metal mesh in thesecond layer for the overlapping, parallel portions. In some examples,to improve optical performance, the metal mesh in the first metal layerand the metal mesh in the second metal layer for a touch electrode canbe non-parallel (e.g., orthogonal), such that overlapping portions canhave a substantially uniform area across the touch electrode (e.g.,within a threshold such as 2 microns-squared or 1.5 microns-squared).

In some examples, to improve SNR and touch sensor panel bandwidth, adielectric layer between the first metal layer and the second metallayer can reduce capacitive coupling therebetween (e.g., parallel platecapacitance). For example, the dielectric layer can have an increasedthickness and/or a reduced dielectric constant to reduce the capacitivecoupling. In some examples, to improve SNR and touch sensor panelbandwidth, the metal mesh in the first metal layer can be flooded,filled or otherwise augmented with a transparent conductive materialelectrically coupled to the metal mesh (optionally separated from thefirst metal layer by a dielectric layer).

In some examples, to reduce cross-talk in a non-differential operatingmode (e.g., stylus or self-capacitance), routing traces can be disposedin a second metal layer beneath touch electrodes implemented in thefirst metal layer (and optionally also in the second metal layer). Insome examples, to reduce cross-talk in a non-differential operating modeand to improve SNR and touch sensor panel bandwidth, the metal mesh fortouch electrodes in the first metal layer can be flooded, filled orotherwise augmented with a transparent conductive material electricallycoupled to the metal mesh, without flooding, filling or otherwiseaugmenting the metal mesh for routing in the first metal layer with thetransparent conductive material. In some examples, the first metal layercan be flooded with transparent conductive material and the transparentconductive material can be etched away from the routing traces in thefirst metal layer.

In some examples, a touch electrode architecture for differential drivewithout differential sense can be implemented. Differential drive canstill reduce the touch-to-display noise. The touch electrodearchitecture for differential drive can simplify the touch electrodearchitecture design because fewer routing traces and fewer bridges arerequired compared with some of the differential drive and differentialsense touch electrode architectures described herein.

In some examples, one or more touch nodes in a touch electrodearchitecture each include a differential pair of row electrodes and adifferential pair of column electrodes. For example, a touch node caninclude a portion of first row electrode Rx0+ and a portion of a secondrow electrode Rx0− (e.g., corresponding to differential inputs for touchsensing), and a portion of a first column electrode Tx0+ and a portionof a second column electrode Tx0− (e.g., corresponding to differential,complimentary outputs of touch driving). The arrangement of the firstand second row electrodes and the first and second column electrodes canresult in two dominant mutual capacitances that are in-phase.Additionally, because the touch node includes portions of the first andsecond row electrodes and the first and second column electrodes, thedifferential cancelation occurs on a per touch node basis rather thanacross two touch nodes. Additionally, the non-dominant (minor) parasiticcapacitance can be reduced by reducing routing lengths and increasingseparation between electrodes that generate parasitic mutualcapacitances.

In some examples, the touch electrode architecture includes fullydifferentially interleaved row and column electrodes within a touchnode. In some examples, the touch electrode architecture differentialfor row (or column) electrodes and pseudodifferential for column (orrow) electrodes.

In some examples, common mode noise can be reduced using spatialseparation and spatial filtering. The spatial separation between touchsignal and common mode noise signal can be achieved using a touchelectrode architecture with reduced pitch for the transmitter andreceiver electrodes.

FIGS. 1A-1E illustrate example systems that can include a touch screenaccording to examples of the disclosure. FIG. 1A illustrates an examplemobile telephone 136 that includes a touch screen 124 according toexamples of the disclosure. FIG. 1B illustrates an example digital mediaplayer 140 that includes a touch screen 126 according to examples of thedisclosure. FIG. 1C illustrates an example personal computer 144 thatincludes a touch screen 128 according to examples of the disclosure.FIG. 1D illustrates an example tablet computing device 148 that includesa touch screen 130 according to examples of the disclosure. FIG. 1Eillustrates an example wearable device 150 that includes a touch screen132 and can be attached to a user using a strap 152 according toexamples of the disclosure. It is understood that a touch screen can beimplemented in other devices as well.

In some examples, touch screens 124, 126, 128, 130 and 132 can be basedon self-capacitance. A self-capacitance based touch system can include amatrix of small, individual plates of conductive material or groups ofindividual plates of conductive material forming larger conductiveregions that can be referred to as touch electrodes or as touch nodeelectrodes (as described below with reference to FIG. 4B). For example,a touch screen can include a plurality of individual touch electrodes,each touch electrode identifying or representing a unique location(e.g., a touch node) on the touch screen at which touch or proximity isto be sensed, and each touch node electrode being electrically isolatedfrom the other touch node electrodes in the touch screen/panel. Such atouch screen can be referred to as a pixelated self-capacitance touchscreen, though it is understood that in some examples, the touch nodeelectrodes on the touch screen can be used to perform scans other thanself-capacitance scans on the touch screen (e.g., mutual capacitancescans). During operation, a touch node electrode can be stimulated withan alternating current (AC) waveform, and the self-capacitance to groundof the touch node electrode can be measured. As an object approaches thetouch node electrode, the self-capacitance to ground of the touch nodeelectrode can change (e.g., increase). This change in theself-capacitance of the touch node electrode can be detected andmeasured by the touch sensing system to determine the positions ofmultiple objects when they touch, or come in proximity to, the touchscreen. In some examples, the touch node electrodes of aself-capacitance based touch system can be formed from rows and columnsof conductive material, and changes in the self-capacitance to ground ofthe rows and columns can be detected, similar to above. In someexamples, a touch screen can be multi-touch, single touch, projectionscan, full-imaging multi-touch, capacitive touch, etc.

In some examples, touch screens 124, 126, 128, 130 and 132 can be basedon mutual capacitance. A mutual capacitance based touch system caninclude electrodes arranged as drive and sense lines that may cross overeach other on different layers (in a double-sided configuration), or maybe adjacent to each other on the same layer (e.g., as described belowwith reference to FIG. 4A). The crossing or adjacent locations can formtouch nodes. During operation, the drive line can be stimulated with anAC waveform and the mutual capacitance of the touch node can bemeasured. As an object approaches the touch node, the mutual capacitanceof the touch node can change (e.g., decrease). This change in the mutualcapacitance of the touch node can be detected and measured by the touchsensing system to determine the positions of multiple objects when theytouch, or come in proximity to, the touch screen. As described herein,in some examples, a mutual capacitance based touch system can form touchnodes from a matrix of small, individual plates of conductive material.

In some examples, touch screens 124, 126, 128, 130 and 132 can be basedon mutual capacitance and/or self-capacitance. The electrodes can bearranged as a matrix of small, individual plates of conductive material(e.g., as in touch node electrodes 408 in touch screen 402 in FIG. 4B)or as drive lines and sense lines (e.g., as in row touch electrodes 404and column touch electrodes 406 in touch screen 400 in FIG. 4A), or inanother pattern. The electrodes can be configurable for mutualcapacitance or self-capacitance sensing or a combination of mutual andself-capacitance sensing. For example, in one mode of operationelectrodes can be configured to sense mutual capacitance betweenelectrodes and in a different mode of operation electrodes can beconfigured to sense self-capacitance of electrodes. In some examples,some of the electrodes can be configured to sense mutual capacitancetherebetween and some of the electrodes can be configured to senseself-capacitance thereof.

FIG. 2 illustrates an example computing system including a touch screenaccording to examples of the disclosure. Computing system 200 can beincluded in, for example, a mobile phone, tablet, touchpad, portable ordesktop computer, portable media player, wearable device or any mobileor non-mobile computing device that includes a touch screen or touchsensor panel. Computing system 200 can include a touch sensing systemincluding one or more touch processors 202, peripherals 204, a touchcontroller 206, and touch sensing circuitry (described in more detailbelow). Peripherals 204 can include, but are not limited to, randomaccess memory (RAM) or other types of memory or storage, watchdog timersand the like. Touch controller 206 can include, but is not limited to,one or more sense channels 208, channel scan logic 210 and driver logic214. Channel scan logic 210 can access RAM 212, autonomously read datafrom the sense channels and provide control for the sense channels. Inaddition, channel scan logic 210 can control driver logic 214 togenerate stimulation signals 216 at various frequencies and/or phasesthat can be selectively applied to drive regions of the touch sensingcircuitry of touch screen 220, as described in more detail below. Insome examples, touch controller 206, touch processor 202 and peripherals204 can be integrated into a single application specific integratedcircuit (ASIC), and in some examples can be integrated with touch screen220 itself.

It should be apparent that the architecture shown in FIG. 2 is only oneexample architecture of computing system 200, and that the system couldhave more or fewer components than shown, or a different configurationof components. In some examples, computing system 200 can include anenergy storage device (e.g., a battery) to provide a power supply and/orcommunication circuitry to provide for wired or wireless communication(e.g., cellular, Bluetooth, Wi-Fi, etc.). The various components shownin FIG. 2 can be implemented in hardware, software, firmware or anycombination thereof, including one or more signal processing and/orapplication specific integrated circuits.

Computing system 200 can include a host processor 228 for receivingoutputs from touch processor 202 and performing actions based on theoutputs. For example, host processor 228 can be connected to programstorage 232 and a display controller/driver 234 (e.g., a Liquid-CrystalDisplay (LCD) driver). It is understood that although some examples ofthe disclosure may be described with reference to LCD displays, thescope of the disclosure is not so limited and can extend to other typesof displays, such as Light-Emitting Diode (LED) displays, includingOrganic LED (OLED), Active-Matrix Organic LED (AMOLED) andPassive-Matrix Organic LED (PMOLED) displays. Display driver 234 canprovide voltages on select (e.g., gate) lines to each pixel transistorand can provide data signals along data lines to these same transistorsto control the pixel display image.

Host processor 228 can use display driver 234 to generate a displayimage on touch screen 220, such as a display image of a user interface(UI), and can use touch processor 202 and touch controller 206 to detecta touch on or near touch screen 220, such as a touch input to thedisplayed UI. The touch input can be used by computer programs stored inprogram storage 232 to perform actions that can include, but are notlimited to, moving an object such as a cursor or pointer, scrolling orpanning, adjusting control settings, opening a file or document, viewinga menu, making a selection, executing instructions, operating aperipheral device connected to the host device, answering a telephonecall, placing a telephone call, terminating a telephone call, changingthe volume or audio settings, storing information related to telephonecommunications such as addresses, frequently dialed numbers, receivedcalls, missed calls, logging onto a computer or a computer network,permitting authorized individuals access to restricted areas of thecomputer or computer network, loading a user profile associated with auser's preferred arrangement of the computer desktop, permitting accessto web content, launching a particular program, encrypting or decoding amessage, and/or the like. Host processor 228 can also perform additionalfunctions that may not be related to touch processing.

Note that one or more of the functions described herein, can beperformed by firmware stored in memory (e.g., one of the peripherals 204in FIG. 2 ) and executed by touch processor 202, or stored in programstorage 232 and executed by host processor 228. The firmware can also bestored and/or transported within any non-transitory computer-readablestorage medium for use by or in connection with an instruction executionsystem, apparatus, or device, such as a computer-based system,processor-containing system, or other system that can fetch theinstructions from the instruction execution system, apparatus, or deviceand execute the instructions. In the context of this document, a“non-transitory computer-readable storage medium” can be any medium(excluding signals) that can contain or store the program for use by orin connection with the instruction execution system, apparatus, ordevice. In some examples, RAM 212 or program storage 232 (or both) canbe a non-transitory computer readable storage medium. One or both of RAM212 and program storage 232 can have stored therein instructions, whichwhen executed by touch processor 202 or host processor 228 or both, cancause the device including computing system 200 to perform one or morefunctions and methods of one or more examples of this disclosure. Thecomputer-readable storage medium can include, but is not limited to, anelectronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus or device, a portable computer diskette(magnetic), a random access memory (RAM) (magnetic), a read-only memory(ROM) (magnetic), an erasable programmable read-only memory (EPROM)(magnetic), a portable optical disc such a CD, CD-R, CD-RW, DVD, DVD-R,or DVD-RW, or flash memory such as compact flash cards, secured digitalcards, USB memory devices, memory sticks, and the like.

The firmware can also be propagated within any transport medium for useby or in connection with an instruction execution system, apparatus, ordevice, such as a computer-based system, processor-containing system, orother system that can fetch the instructions from the instructionexecution system, apparatus, or device and execute the instructions. Inthe context of this document, a “transport medium” can be any mediumthat can communicate, propagate or transport the program for use by orin connection with the instruction execution system, apparatus, ordevice. The transport medium can include, but is not limited to, anelectronic, magnetic, optical, electromagnetic or infrared wired orwireless propagation medium.

Touch screen 220 can be used to derive touch information at multiplediscrete locations of the touch screen, referred to herein as touchnodes. Touch screen 220 can include touch sensing circuitry that caninclude a capacitive sensing medium having a plurality of drive lines222 and a plurality of sense lines 223. It should be noted that the term“lines” is sometimes used herein to mean simply conductive pathways, asone skilled in the art will readily understand, and is not limited toelements that are strictly linear, but includes pathways that changedirection, and includes pathways of different size, shape, materials,etc. Drive lines 222 can be driven by stimulation signals 216 fromdriver logic 214 through a drive interface 224, and resulting sensesignals 217 generated in sense lines 223 can be transmitted through asense interface 225 to sense channels 208 in touch controller 206. Inthis way, drive lines and sense lines can be part of the touch sensingcircuitry that can interact to form capacitive sensing nodes, which canbe thought of as touch picture elements (touch pixels) and referred toherein as touch nodes, such as touch nodes 226 and 227. This way ofunderstanding can be particularly useful when touch screen 220 is viewedas capturing an “image” of touch (“touch image”). In other words, aftertouch controller 206 has determined whether a touch has been detected ateach touch nodes in the touch screen, the pattern of touch nodes in thetouch screen at which a touch occurred can be thought of as an “image”of touch (e.g., a pattern of fingers touching the touch screen). As usedherein, an electrical component “coupled to” or “connected to” anotherelectrical component encompasses a direct or indirect connectionproviding electrical path for communication or operation between thecoupled components. Thus, for example, drive lines 222 may be directlyconnected to driver logic 214 or indirectly connected to drive logic 214via drive interface 224 and sense lines 223 may be directly connected tosense channels 208 or indirectly connected to sense channels 208 viasense interface 225. In either case an electrical path for drivingand/or sensing the touch nodes can be provided.

FIG. 3A illustrates an exemplary touch sensor circuit 300 correspondingto a self-capacitance measurement of a touch node electrode 302 andsensing circuit 314 according to examples of the disclosure. Touch nodeelectrode 302 can correspond to a touch electrode 404 or 406 of touchscreen 400 or a touch node electrode 408 of touch screen 402. Touch nodeelectrode 302 can have an inherent self-capacitance to ground associatedwith it, and also an additional self-capacitance to ground that isformed when an object, such as finger 305, is in proximity to ortouching the electrode. The total self-capacitance to ground of touchnode electrode 302 can be illustrated as capacitance 304. Touch nodeelectrode 302 can be coupled to sensing circuit 314. Sensing circuit 314can include an operational amplifier 308, feedback resistor 312 andfeedback capacitor 310, although other configurations can be employed.For example, feedback resistor 312 can be replaced by a switchedcapacitor resistor in order to minimize a parasitic capacitance effectthat can be caused by a variable feedback resistor. Touch node electrode302 can be coupled to the inverting input (−) of operational amplifier308. An AC voltage source 306 (V_(ac)) can be coupled to thenon-inverting input (+) of operational amplifier 308. Touch sensorcircuit 300 can be configured to sense changes (e.g., increases) in thetotal self-capacitance 304 of the touch node electrode 302 induced by afinger or object either touching or in proximity to the touch sensorpanel. Output 320 can be used by a processor to determine the presenceof a proximity or touch event, or the output can be inputted into adiscrete logic network to determine the presence of a proximity or touchevent.

FIG. 3B illustrates an exemplary touch sensor circuit 350 correspondingto a mutual-capacitance drive line 322 and sense line 326 and sensingcircuit 314 according to examples of the disclosure. Drive line 322 canbe stimulated by stimulation signal 306 (e.g., an AC voltage signal).Stimulation signal 306 can be capacitively coupled to sense line 326through mutual capacitance 324 between drive line 322 and the senseline. When a finger or object 305 approaches the touch node created bythe intersection of drive line 322 and sense line 326, mutualcapacitance 324 can change (e.g., decrease) (e.g., due to capacitivecoupling indicated by capacitances C_(FD) 311 and C_(FS) 313, which canbe formed between drive line 322, finger 305 and sense line 326). Thischange in mutual capacitance 324 can be detected to indicate a touch orproximity event at the touch node, as described herein. The sense signalcoupled onto sense line 326 can be received by sensing circuit 314.Sensing circuit 314 can include operational amplifier 308 and at leastone of a feedback resistor 312 and a feedback capacitor 310. FIG. 3Billustrates a general case in which both resistive and capacitivefeedback elements are utilized. The sense signal (referred to as Vin)can be inputted into the inverting input of operational amplifier 308,and the non-inverting input of the operational amplifier can be coupledto a reference voltage V_(ref). Operational amplifier 308 can drive itsoutput to voltage V_(o) to keep V_(in) substantially equal to V_(ref),and can therefore maintain V_(in) constant or virtually grounded. Aperson of skill in the art would understand that in this context, equalcan include deviations of up to 15%. Therefore, the gain of sensingcircuit 314 can be mostly a function of the ratio of mutual capacitance324 and the feedback impedance, comprised of resistor 312 and/orcapacitor 310. The output of sensing circuit 314 Vo can be filtered andheterodyned or homodyned by being fed into multiplier 328, where Vo canbe multiplied with local oscillator 330 to produce V_(detect).V_(detect) can be inputted into filter 332. One skilled in the art willrecognize that the placement of filter 332 can be varied; thus, thefilter can be placed after multiplier 328, as illustrated, or twofilters can be employed: one before the multiplier and one after themultiplier. In some examples, there can be no filter at all. The directcurrent (DC) portion of V_(detect) can be used to determine if a touchor proximity event has occurred. Note that while FIGS. 3A-3B indicatethe demodulation at multiplier 328 occurs in the analog domain, outputVo may be digitized by an analog-to-digital converter (ADC), and blocks328, 332 and 330 may be implemented in a digital fashion (e.g., 328 canbe a digital demodulator, 332 can be a digital filter, and 330 can be adigital NCO (Numerical Controlled Oscillator).

Referring back to FIG. 2 , in some examples, touch screen 220 can be anintegrated touch screen in which touch sensing circuit elements of thetouch sensing system can be integrated into the display pixel stack-upsof a display. The circuit elements in touch screen 220 can include, forexample, elements that can exist in LCD or other displays (LED display,OLED display, etc.), such as one or more pixel transistors (e.g., thinfilm transistors (TFTs)), gate lines, data lines, pixel electrodes andcommon electrodes. In a given display pixel, a voltage between a pixelelectrode and a common electrode can control a luminance of the displaypixel. The voltage on the pixel electrode can be supplied by a data linethrough a pixel transistor, which can be controlled by a gate line. Itis noted that circuit elements are not limited to whole circuitcomponents, such as a whole capacitor, a whole transistor, etc., but caninclude portions of circuitry, such as only one of the two plates of aparallel plate capacitor.

FIG. 4A illustrates touch screen 400 with touch electrodes 404 and 406arranged in rows and columns according to examples of the disclosure.Specifically, touch screen 400 can include a plurality of touchelectrodes 404 disposed as rows, and a plurality of touch electrodes 406disposed as columns. Touch electrodes 404 and touch electrodes 406 canbe on the same or different material layers on touch screen 400, and canintersect with each other, as illustrated in FIG. 4A. In some examples,the electrodes can be formed on opposite sides of a transparent(partially or fully) substrate and from a transparent (partially orfully) semiconductor material, such as ITO, though other materials arepossible. Electrodes displayed on layers on different sides of thesubstrate can be referred to herein as a double-sided sensor. In someexamples, touch screen 400 can sense the self-capacitance of touchelectrodes 404 and 406 to detect touch and/or proximity activity ontouch screen 400, and in some examples, touch screen 400 can sense themutual capacitance between touch electrodes 404 and 406 to detect touchand/or proximity activity on touch screen 400.

Although FIG. 4A illustrates touch electrodes 404 and touch electrodes406 as rectangular electrodes, in some examples, other shapes andconfigurations are possible for row and column electrodes. For example,in some examples, some or all row and column electrodes can be formedfrom multiple touch electrodes formed on one side of substrate from atransparent (partially or fully) semiconductor material. The touchelectrodes of a particular row or column can be interconnected bycoupling segments and/or bridges. Row and column electrodes formed in alayer on the same side of a substrate can be referred to herein as asingle-sided sensor. As described in more detail below, row and columnelectrodes can have other shapes. Additionally, although primarilydescribed in terms of a row-column configuration, it is understood thatin some examples, the same principles can be applied to two-axis arrayof touch nodes in a non-rectilinear arrangement.

FIG. 4B illustrates touch screen 402 with touch node electrodes 408arranged in a pixelated touch node electrode configuration according toexamples of the disclosure. Specifically, touch screen 402 can include aplurality of individual touch node electrodes 408, each touch nodeelectrode identifying or representing a unique location on the touchscreen at which touch or proximity (i.e., a touch or proximity event) isto be sensed, and each touch node electrode being electrically isolatedfrom the other touch node electrodes in the touch screen/panel, aspreviously described. Touch node electrodes 408 can be on the same ordifferent material layers on touch screen 402. In some examples, touchscreen 402 can sense the self-capacitance of touch node electrodes 408to detect touch and/or proximity activity on touch screen 402, and insome examples, touch screen 402 can sense the mutual capacitance betweentouch node electrodes 408 to detect touch and/or proximity activity ontouch screen 402.

In some examples, some or all of the touch electrodes of a touch screencan be formed from a metal mesh in one or more layers. FIG. 5illustrates an example touch screen stack-up including a metal meshlayer according to examples of the disclosure. Touch screen 500 caninclude a substrate 509 (e.g., a printed circuit board) upon whichdisplay components 508 (e.g., LEDs or other light emitting componentsand circuitry) can be mounted. In some examples, the display components508 can be partially or fully embedded in substrate 509 (e.g., thecomponents can be placed in depressions in the substrate). Substrate 509can include routing traces in one or more layers to route the displaycomponents (e.g., LEDs) to display driving circuitry (e.g., displaydriver 234). The stack-up of touch screen 500 can also include one ormore passivation layers deposited over the display components 508. Forexample, the stack-up of touch screen 500 illustrated in FIG. 5 caninclude an intermediate layer/passivation layer 507 (e.g., transparentepoxy), between first metal layer 516 and second metal layer 506, andpassivation layer 517. Passivation layers 507 and 517 can planarize thesurface for respective metal mesh layers. Additionally, the passivationlayers can provide electrical isolation (e.g., between metal mesh layersand between the LEDs and a metal mesh layer). Metal mesh layer 516(e.g., copper, silver, etc.) can be deposited on the planarized surfaceof the passivation layer 517 over the display components 508, and metalmesh layer 506 (e.g., copper, silver, etc.) can be deposited on theplanarized surface of passivation layer 507. In some examples, thepassivation layer 517 can include material to encapsulate the displaycomponents to protect them from corrosion or other environmentalexposure. Metal mesh layer 506 and/or metal mesh layer 516 can include apattern of conductor material in a mesh pattern. In some examples, metalmesh layer 506 and metal mesh layer 516 can be coupled by one or morevias (e.g., through intermediate layer/passivation layer 507.Additionally, although not shown in FIG. 5 , a border region around thedisplay active area can include metallization (or other conductivematerial) that may or may not be a metal mesh pattern. In some examples,metal mesh is formed of a non-transparent material, but the metal meshwires are sufficiently thin and sparse to appear transparent to thehuman eye. The touch electrodes (and some routing) as described hereincan be formed in the metal mesh layer(s) from portions of the metalmesh. In some examples, polarizer 504 can be disposed above the metalmesh layer 506 (optionally with another planarization layer disposedover the metal mesh layer 506). Cover glass (or front crystal) 502 canbe disposed over polarizer 504 and form the outer surface of touchscreen 500. It is understood that although two metal mesh layers (andtwo corresponding planarization layers) are illustrated, in someexamples more or fewer metal mesh layers (and correspondingplanarization layers) can be implemented. Additionally, it is understoodthat in some examples, display components 508, substrate 509 and/orpassivation layer 517 can be replaced by a thin-film transistor (TFT)LCD display (or other types of displays), in some examples.Additionally, it is understood that polarizer 504 can include one ormore transparent layers including a polarizer, adhesive layers (e.g.,optically clear adhesive) and protective layers.

As described herein, in some examples, touch electrodes of the touchscreen can be differentially driven and/or differentially sensed.Differential driving and differential sensing can reduce noise in thetouch and/or display systems of the touch screen that may arise due tothe proximity of the touch system to the display system. For example,the touch screen may include touch electrodes that are disposedpartially or entirely over the display (e.g., a touch sensor panellaminated to a display, or otherwise integrated on or in the displaystack-up), or otherwise in proximity to the display. For example, touchelectrodes (e.g., formed of metal mesh) may capacitive couple withdisplay electrodes (e.g., cathode electrodes), which can result indisplay operation injecting noise into the touch electrodes (e.g.,reducing the touch sensing performance). Additionally, touch operation(e.g., stimulating touch electrodes) can result in injecting noise inthe display (e.g., introducing image artifacts). Differential drivingand differential sensing can cause most noise coupled into the sensingcircuitry due to the display to be common mode and the common mode noisecan be rejected by the differential sensing circuitry. Likewise, thedifferential driving can reduce local imbalance on display electrodesfrom touch electrodes. Thus, differential driving can cause the cathodeof the display to shield the display from the touch operation, which canlower injected noise into the display system (and/or allow for moreheadroom to increase the amplitude of drive signals compared with anon-differential driving scheme).

As described herein, differential driving refers to concurrently drivinga first of two drive electrodes with a first stimulation signal (e.g., asine wave, a square wave, etc.) and a second of two drive electrodeswith a second stimulation signal that is 180 degrees out of phase withthe first stimulation signal (e.g., an inverted sine wave, an invertedsquare wave, etc.). In some examples, the first and second stimulationsignals can be driven by a differential driving circuit. In someexamples, the first and second stimulation signals can be driven by twosingle-ended driving circuits. Differential driving can be extended formore than two drive electrodes such that for N concurrently driven driveelectrodes, one half of the drive electrodes can be concurrently drivenwith a first set of stimulation signals and the other half of the driveelectrodes can be concurrently driven with a second set of stimulationsignals complimentary to the first set (e.g., an inverted version of thefirst set). As described herein, differential sensing refers to sensingtwo sense electrodes differentially. For example, a first of the twosense electrodes can be input into a first terminal of a differentialamplifier (e.g., the inverting input) and a second of the two senseelectrodes can be input into a second terminal of the differentialamplifier (e.g., the non-inverting input). In some examples, thedifferential sensing can be implemented with two single-ended amplifiers(e.g., sensing circuit 314) each sensing one sense electrode and twoADCs configured to convert the outputs of the two single-ended amplifierto a digital output. The differential can be computed between thedigital outputs of the two amplifiers (e.g., in the analog or digitaldomain). In some examples, using differential amplifiers (rather thantwo single-ended amplifiers) may provide improved input referred noisefor the differential part of the signal (removing common mode noise, andreducing the dynamic range). In some examples, using single-endedamplifiers (rather than a differential amplifiers) may provide outputrepresentative of common mode noise that may be useful for the system.

FIG. 6A illustrates a symbolic representation of a touch sensor panelimplementing differential sensing according to examples of thedisclosure. FIG. 6A illustrates a touch sensor panel 600 including rowelectrodes 602A-602D (also referred to as drive electrodes or lines) andcolumn electrodes 604A-604H (also referred to as sense electrodes orlines). Touch sensor panel 600 can also include drive circuitry (e.g.,drivers/transmitters 606A-606D that can correspond to driver logic 214)configured to drive row electrodes 602A-602D and sense circuitry (e.g.,differential amplifiers 608A-608D that can correspond to a part of sensechannels 208) configured to sense column electrodes 604A-604H. It shouldbe understood that although the terms “row” and “column” may be usedthroughout this disclosure in conjunction with figures showing row andcolumn arrangements, these terms are used for convenience ofexplanation, and actual orientations can be interchanged in accordancewith examples of the disclosure.

In particular, touch sensor panel 600 illustrates a touch sensor panelwith four row electrodes 602A-602D and eight column electrodes604A-604H. Each driver/transmitter 606A-606D can be coupled to arespective one of the row electrodes 602A-602D (e.g., driver/transmitter606A can be coupled to row electrode 602A, driver/transmitter 606B canbe coupled to row electrode 602B, etc.). Each differential amplifier608A-608D can be coupled to a respective pair of the column electrodes604A-604H (e.g., differential amplifier 608A can be coupled to columnelectrodes 604A-604B, differential amplifier 608B can be coupled tocolumn electrodes 604C-604D, etc.). The differential amplifiers608A-608D can each include a common mode feedback circuit (e.g.,including resistive and/or capacitive circuit elements) to keep theinputs at virtual ground. A first column electrode of the respectivepair of column electrodes can be coupled to an inverting terminal ofcorresponding differential amplifier and a second column electrode ofthe respective pair of column electrodes can be coupled to thenon-inverting terminal of the corresponding differential amplifier.

Touch sensor panel 600 can be driven and sensed to detect sixteencapacitance values. Technically, a mutual capacitance (electrostaticfringe field) may be formed between the intersection (or adjacency) ofeach row electrode and each column electrode. For example, a firstmutual capacitance, C′₀, can be formed between row electrode 602A andcolumn electrode 604A and a second mutual capacitance, C₀, can be formedbetween row electrode 602A and column electrode 604B. However, asrepresented in FIG. 6A, the amount of conductive material at some of theintersections (or adjacencies) of row electrodes and column electrodesmay be smaller than the amount of conductive material at theintersections (or adjacencies) of other row electrodes. For example, asrepresented in FIG. 6A, the amount of conductive material at theintersection of row electrode 602A and column electrode 604A can be lessthan the amount of conductive material at the intersection of rowelectrode 602A and column electrode 604B. As a result, the mutualcapacitance (electrostatic fringe field) of the former can be relativelynegligible with respect to the latter, such that the mutual capacitanceof the former can be essentially ignored, in some examples. (In someexamples, the relatively negligible capacitance can be reduced byincreasing the distance between certain portions of the row and columnelectrodes and or electrically isolating certain portions of the row andcolumn electrodes.) For example, the mutual capacitance between rowelectrode 602A and column electrode 604A (C′₀) can be relatively smallcompared with the mutual capacitance between row electrode 602A andcolumn electrode 604B (C₀) or the mutual capacitance of row electrode602B and column electrode 604A (C₁).

For each respective driver and a respective differential sense amplifierin FIG. 6A, one of the mutual capacitances can be a dominant (or major)mutual capacitance and one of the mutual capacitances can be a minormutual capacitance (where the mutual capacitance/electrostatic fringefield can be a function of the amount of conductive material andarrangement of conductive material). In some examples, the dominantmutual capacitance can correspond to fringe field coupling above athreshold for the respective driver/differential amplifier (e.g., above80%, 85%, 90%, 95%, etc.) and the minor mutual capacitance cancorrespond to fringe field coupling below a threshold for the respectivedriver/differential amplifier (e.g., below 20%, 15%, 10%, 5%, etc.).Thus, the sixteen values measured for touch sensor panel 600 canrepresent the dominant mutual capacitances by virtue of the pattern ofconductive material for the row electrodes and column electrodes. Forexample, C₀ can represent a dominant mutual capacitance between rowelectrode 602A and column electrode 604B, C₁ can represent a dominantmutual capacitance between row electrode 602B and column electrode 604A,C₂ can represent a dominant mutual capacitance between row electrode602C and column electrode 604B, and C₃ can represent a dominant mutualcapacitance between row electrode 602D and column electrode 604A. Eachof these dominant mutual capacitances can represent an effective touchnode for the touch sensor panel. In some examples, the “effective touchnode” described herein can be alternatively referred to as the “touchnode” because it can represent the dominant mutual capacitance for theregion of the touch sensor panel.

The dominant mutual capacitance (relatively high electrostatic fringefield) and minor mutual capacitances (relatively low electrostaticfringe field) can be spatially alternating, in some examples. Thespatially alternating can appear along one or both dimensions. Forexample, for driver 606A/row electrode 602A, dominant capacitances C₀,C₄, C₈, C₁₂ (formed with column electrode 604B, 604D, 604F, 604H and theinverting terminal of differential amplifiers 608A-608D) can alternatespatially with minor capacitances C′₀, C′₄, C′₈, C₁₂. For the remainingdrivers/row electrodes, the dominant and minor capacitances canalternate spatially as well. For the inverting terminal of differentialamplifier 608A/column electrode 604B, dominant capacitances C₀ and C₂(formed with row electrode 602A and 602C and corresponding driver 606Aand 606C) can alternate spatially with minor capacitances C′₁ and C′₃.For the non-inverting terminal of differential amplifier 608A/columnelectrode 604A, dominant capacitances C₁ and C₃ (formed with rowelectrode 602B and 602D and corresponding driver 606B and 606D) canalternate spatially with minor capacitances C′₀ and C′₂. For theremaining differential amplifier/column electrodes, the dominant andminor capacitances can alternate spatially as well.

During operation, row electrodes 602A-602D can be stimulated with amulti-stimulus pattern of drive signals (H0-H3), and column electrodes604A-604D can be differentially sensed using differential amplifiers608A-608D. For example, the multi-stimulus pattern can be a Hadamardmatrix (e.g., a 4×4 matrix including “1” and “−1” values, indexed todriver and drive step) applied to a common stimulation signal (e.g., asine wave, a square wave, etc.) to encode the drive signals. Themulti-stimulus pattern can allow for the dominant mutual capacitances tobe measured and decoded based on the multi-stimulus drive pattern.Differentially sensing the column electrodes can remove common modenoise from the touch measurements. It should be understood that althoughtouch sensor panel 600 includes sixteen dominant capacitance values(e.g., corresponding to sixteen touch nodes in a 4×4 array), that thetouch sensor panel can be scaled up or down to include fewer or moretouch nodes.

In some examples, to reduce noise and thereby improve signal-to-noiseratio (SNR), touch sensor panel 600 can be modified to implementdifferential driving. For example, rather than implementing one driveline per row of effective touch nodes, two drive lines can be used perrow of effective touch nodes. FIG. 6B illustrates a symbolicrepresentation of a touch sensor panel implementing differential drivingand differential sensing according to examples of the disclosure. FIG.6B illustrates a touch sensor panel 510 including row electrodes602A-602D and row electrodes 602A′-602D′ (eight row electrodes) andcolumn electrodes 604A-604H (eight column electrodes). Touch sensorpanel 600 can also include drive circuitry (e.g., drivers/transmitters606A-606D and drivers/transmitters 606A′-606D′) configured to drive rowelectrodes 602A-602D and 602A′-602D′ and sense circuitry (e.g.,differential amplifiers 608A-608D) configured to sense column electrodes604A-604H.

Each driver/transmitter 606A-606D, 606A′-606D′ can be coupled to arespective one of the row electrodes 602A-602D, 602A′-602D′ and eachdifferential amplifier 608A-608D can be coupled to a respective pair ofthe column electrodes 604A-604H. Despite doubling the row electrodescompared with touch sensor panel 600, touch sensor panel 510 can bedriven and sensed to detect sixteen dominant mutual capacitance values(represented in FIG. 6A by the relatively large amount of conductivematerial of some row electrodes and column electrodes). The sixteendominant mutual capacitance values can represent a 4×4 array of touchnodes for the touch sensor panel. During operation, row electrodes602A-602D and row electrodes 602A′-602D′ can be stimulated with amulti-stimulus pattern of drive signals (H0-H3 and H0′-H3′), and columnelectrodes 604A-604D can be differentially sensed using differentialamplifiers 608A-608D. In some examples, the multi-stimulus pattern canbe two orthogonal Hadamard matrices (e.g., each a 4×4 matrix including“1” and “−1” values, indexed to driver and drive step) applied to acommon stimulation signal (e.g., a sine wave, a square wave, etc.) toencode the drive signals. In some examples, the multi-stimulus patterncan be one Hadamard matrix and its complimentary signals (180 degreesout of phase) applied to a common stimulation signal (e.g., a sine wave,a square wave, etc.) to encode the drive signals. The multi-stimuluspattern can allow for the dominant mutual capacitances to be measuredand decoded based on the multi-stimulus drive pattern. Differentiallysensing the column electrodes can remove common mode noise from thetouch measurements. It should be understood that although touch sensorpanel 510 includes sixteen dominant capacitance values (e.g.,corresponding to sixteen touch nodes), that the touch sensor panel canbe scaled up or down to include fewer or more touch nodes.

As described with respect to FIG. 6A, the dominant mutual capacitance(relatively high electrostatic fringe field) and minor mutualcapacitances (relatively low electrostatic fringe field) can bespatially patterned in FIG. 6B. In some examples, the spatialalternating can appear along one or both dimensions. For example, fordriver 606A/row electrode 602A, dominant capacitances can be formed atintersections with column electrodes 604B and 604F, with minorcapacitances formed at the remaining intersections with columnselectrodes 604A, 604C-604E, 604G and 604H. In a similar manner, driver606B/row electrode 602A′, dominant capacitances can be formed atintersections with column electrodes 604D and 604H, with minorcapacitances formed at the remaining intersections with columnselectrodes 604A-604C and 604E-604G. The spatial pattern of dominant andminor capacitances can repeat for the remaining rows. For the invertingterminal of differential amplifier 608A/column electrode 604B, dominantcapacitances C₀ and C₂ can be formed at intersections with row electrode602A and 602C and corresponding driver 606A and 606C, with minorcapacitances at the remaining intersections for column electrode 604B.For the non-inverting terminal of differential amplifier 608A/columnelectrode 604A, dominant capacitances C₁ and C₃ can be formed atintersections with row electrode 602B and 602D, with minor capacitancesat the remaining intersections for column electrode 604A. The spatialpattern of dominant and minor capacitances can repeat for the remainingcolumns. Thus, along the rows and along the columns, the dominantcapacitances can be spatially separated from each other by three minorcapacitances in the spatial pattern of FIG. 6B.

FIG. 7A illustrates a portion of a touch sensor panel that can be usedto implementing differential driving and/or differential sensingaccording to examples of the disclosure. Touch sensor panel 700 can havemutual capacitance/electrostatic fringe field coupling with a spatialpattern, in a manner similar to described above with respect to FIG. 5B.FIG. 7A illustrates a touch sensor panel 700 including row electrodes702A-702F and column electrodes 704A-704F. Touch sensor panel 700 canalso include drive circuitry (e.g., drivers/transmitter that cancorrespond to driver logic 214 or drivers/transmitter 606A-606D′)configured to drive column electrodes 704A-704F and sense circuitry(e.g., differential amplifiers including common mode feedback circuitsthat can correspond to a part of sense channels 208 or differentialamplifiers 608A-608D) configured to sense row electrodes 702A-702F. Inparticular, FIG. 7A illustrates touch sensor panel 700 with six rowelectrodes 702A-602F and six column electrodes 704A-704F. Eachdriver/transmitter can be coupled to a respective one of the columnelectrodes 704A-704F and each differential amplifier can be coupled to arespective pair of row electrodes 702A-702F. A first row electrode ofthe respective pair of row electrodes can be coupled to an invertingterminal of a corresponding differential amplifier and a second rowelectrode of the respective pair of row electrodes can be coupled to thenon-inverting terminal of the corresponding differential amplifier. Forsimplicity of illustration, FIG. 7A illustrates differential driver 706configured to output complimentary drive signals D0+ and D0− to routingtraces for column electrodes 704A-704B, but it should be understood thatadditional drivers can be included to drive additional columnelectrodes. Likewise, for simplicity of illustration, FIG. 7Aillustrates differential amplifier 708 (or 708′) configured to receivingand differentially sensing signals from routing traces for rowelectrodes 702A-702B, but it should be understood that additionalreceivers can be included to sense additional row electrodes.

Column electrodes 704A-704F can include multiple conductive segmentsinterconnected by routing. For example, column electrode 704A includestwo conductive segments (e.g., each having a “H” shape) forming theeffective touch nodes of touch sensor panel 700 that are connected byrouting such as routing 705A. Likewise, row electrodes 702A-702F caninclude multiple conductive segments interconnected by routing. Forexample, row electrode 702A includes conductive segments 702A′ and 702A″(e.g., with a shape of a rectangle with an “H” shaped cutout) formingthe effective touch nodes of touch sensor panel 700 that are connectedby routing such as routing 702A′″. In some examples, as illustrated inFIG. 7A, the sense electrodes be contiguous such that the multiplesegments 702A′ and 702A″ and routing traces 702A′″ can be considered onerow electrode. It is understood although similar shading is used for therow electrode pairs in each row and similar shading is used for columnelectrodes within each row and an alternative row, that these shadingsare for ease of illustration and do not necessarily indicate that theelectrodes are coupled together. For example, each row electrode can beelectrically isolated and coupled to a different input of the sensingcircuitry. Column electrodes in alternating rows may be electricallyconnected, but each column of column electrodes may be coupled todifferent outputs of stimulation circuitry.

Touch sensor panel 700 can be viewed as including a two dimensionalarray (three rows and three columns) of effective touch nodes. Eacheffective touch node of touch sensor panel 700 can measure a capacitancedominated by the capacitance between the conductive segments ofrespective row and column electrodes (formed from interlockingconductive segments). For example, the mutual capacitance betweensegment 702A′ of row electrode 702A and the upper segment of columnelectrode 704A can dominate for the effective touch node correspondingto the region of column 1 and row 1 of touch sensor panel 700. Thecapacitive contributions of the routing portions of nearby row or columnelectrodes can form minor mutual capacitances that can be negligible incomparison (e.g., the contribution from the routing portion 705A or 705Bof column electrode 704A or 704B to segment 702A′ of row electrode702A). As a result of the pattern of the row and column electrodes, thedominant/minor mutual capacitance/electrostatic fringe field couplingcan be spatially patterned, as described herein. For example, columnelectrode 704A can dominantly couple with row electrodes 702A and 702E,with minor coupling for row electrodes 702B, 702C, 702D and 702F. Rowelectrode 702A can dominantly couple with column electrode 704A and704E, with minor coupling for column electrodes 704B, 704C, 704D and704F. The spatial pattern of dominant/minor mutualcapacitance/electrostatic fringe field coupling can continue in asimilar manner. It should be noted that the size of the routing may beexaggerated for illustration purposes and the routings size relative tothe conductive segments may be even smaller than shown. In someexamples, the conductive segments of row and column electrodes areformed in a common layer (i.e., the same layer of the touch sensorpanel), such as in second metal layer 506. In some examples, the routingof the row and column electrodes can be formed at least in part in thecommon layer. In some examples, some or all of the routing can be in adifferent layer, such as in first metal layer 516 (e.g., to allow forelectrical separation where the electrodes overlap in the illustration,and to further reduce the contribution of the routing to the capacitanceat the effective touch nodes).

As illustrated in FIG. 7A, touch sensor panel 700 can include three rowsand three columns of touch nodes (e.g., effective touch nodes). Forexample, a first column of touch nodes can be formed primarily from theconductive segments of row electrodes 702A, 702C, 702E and theconductive segments of column electrodes 704A, 704B. As another example,a second column of touch nodes can be formed primarily from theconductive segments of row electrodes 702B, 702D, 702F and theconductive segments of column electrodes 704C, 704D. In a similarmanner, a first row of touch nodes can be formed primarily from theconductive segments of row electrodes 702A and 702B and the conductivesegments of column electrodes 704A, 704C, and 704E. As another example,a second row of touch nodes can be formed primarily from the conductivesegments of row electrodes 702C and 702D and the conductive segments ofcolumn electrodes 704B, 704D, and 704F.

During operation, the drive circuitry coupled to the column electrodescan differentially drive the column electrodes and differentialamplifiers can differentially sense the row electrodes. For example,column electrodes 704A-704F can be stimulated (e.g., concurrently) witha multi-stimulus pattern of complimentary drive signals (D0+/−, D1+/−and D2+/−) over multiple scan steps. Although a 3×3 array of touch nodesis shown for simplicity of illustration, it should be understood thatthe array can be expanded to a 4×4 array (or a larger sized array) usingcomplimentary drive signals (D0+/−, D1+/−D2+/−, and D3+/−, for example(alternatively represented as D0-D3 and D0′-D3′). For example, themulti-stimulus pattern can be a Hadamard matrix including values of 1(for phase of 0 degrees) and −1 (for phase of 180 degrees) applied to acommon stimulation signal (e.g., a sine wave at frequency f₁) to encodethe drive signals, allowing for the dominant mutual capacitances to bemeasured and decoded based on the multi-stimulus drive pattern. Forexample, for a 4×4 array, D0-D3 can be represented by the followingHadamard matrix:

$\begin{bmatrix}1 & {- 1} & {- 1} & {- 1} \\{- 1} & 1 & {- 1} & {- 1} \\{- 1} & {- 1} & 1 & {- 1} \\{- 1} & {- 1} & {- 1} & 1\end{bmatrix}$

wherein each row in the matrix represents a step of the scan, and eachcolumn representing one of the drive signals D0-D3, such that the valuesof the matrix represent the phase applied to the common stimulationsignal for D0, D1, D2, and D3 for each step. For each drive signal inthe multi-stimulus pattern of drive signals, a complimentary signal canbe applied concurrently (e.g., drive signals D0-D3 and D0′-D3′). Forexample, the first row corresponding to the first scan step indicatesthat drive signal D0 has a phase of 180 degrees. Drive signal D0 can beapplied differentially to column electrodes 704A and 704B such that thesignal applied to column electrode 704A is 180 degrees out of phase withthe signal applied to column electrode 704B. According to the exampleHadamard matrix above driver/buffer 706 outputs a drive signal with aphase of 0 and outputs a complimentary drive signal with a phase of 180degree. In a similar manner, two complimentary drive signals can beapplied to the touch sensor panel for each of the drive signals D0-D3 ina 4×4 array. The drive signals can be output for the drive linesaccording to the remaining rows of the Hadamard matrix for thesubsequent three scan steps.

Considering an example receiver of differential amplifier 708 (or 708′),for drive signal D0 at the touch node for row 1, column 1, the minorcoupling between column electrode 704B by virtue of routing trace 705Band row electrode 702A can be relatively small compared with thedominant coupling of between column electrode 704A and row electrode702A (e.g., via fringe field coupling therebetween). The dominantcoupling can be represented by capacitance C0 (for row 1, column 1) thatis coupled to the non-inverting (positive) input terminal ofdifferential amplifier 708. Thus, a current proportional to C0 canappear at the output of differential amplifier 708. In a similar manner,for drive signal D1, the dominant coupling between column electrode 704Cand row electrode 702B can be represented by capacitance C1 (for row 1,column 2), that is coupled to the inverting (negative) input terminal ofdifferential amplifier 708 and a current proportional to C1 can appearat the output of differential amplifier 708. The additional dominantcouplings for differential amplifier 708 are similar for the remainingcolumns corresponding to the first row. Thus, the output of themeasurement of the current by differential amplifier 708 for the firstscan step can be proportional to C0-C1-C2-C3 for an array with fourcolumns. Following the same procedure for the remaining three steps, theoutput for the four scan steps can be represented as a vectorproportional to:

$\begin{bmatrix}{C_{0} - C_{1} - C_{2} - C_{3}} \\{{- C_{0}} + C_{1} - C_{2} - C_{3}} \\{{- C_{0}} - C_{1} + C_{2} - C_{3}} \\{{- C_{0}} - C_{1} - C_{2} + C_{3}}\end{bmatrix}$

This vector encoding can be decoded or inverted by the matrix,extracting the individual capacitances, but with an effectiveintegration time of the entire measurement, as shown by the equationbelow:

$\begin{bmatrix}C_{0} \\C_{1} \\C_{2} \\C_{3}\end{bmatrix} = {\begin{bmatrix}{1/4} & {{- 1}/4} & {{- 1}/4} & {{- 1}/4} \\{{- 1}/4} & {1/4} & {{- 1}/4} & {{- 1}/4} \\{{- 1}/4} & {{- 1}/4} & {1/4} & {{- 1}/4} \\{{- 1}/4} & {{- 1}/4} & {{- 1}/4} & {1/4}\end{bmatrix}\begin{bmatrix}{C_{0} - C_{1} - C_{2} - C_{3}} \\{{- C_{0}} + C_{1} - C_{2} - C_{3}} \\{{- C_{0}} - C_{1} + C_{2} - C_{3}} \\{{- C_{0}} - C_{1} - C_{2} + C_{3}}\end{bmatrix}}$

Although FIG. 7A illustrates the drive circuitry as including threedifferential drivers 706A-706C outputting a signal and its compliment,it should be understood that other implementations are possible. Forexample, six discreet drivers can be used, where each of differentialdrivers outputs a signal or its compliment. In some examples, thecomplimentary drive signals can be applied to adjacent column electrodessuch that the net electrical effect due to the drive signal can be zero(or within a threshold of zero) localized to the two column electrodes.For example, adjacent column electrodes 704A and 704B (or 704B and 704C)can be driven with the complimentary signals and result in a net zero(or near zero) electrical effect (e.g., to reduce noise from the touchsystem coupled into the display system). Although applying complimentarysignals is shown in adjacent electrodes, it is understood that thecomplimentary signal can be applied to a non-adjacent column electrodesuch that the net electrical effect may be zero (or within a thresholdof zero) for the touch sensor panel, but may not be zero at localizedregions of the touch sensor panel.

For each column of touch nodes in touch sensor panel 700, a first drivesignal and a second drive signal can be applied. For example, column 1of touch sensor panel can be driven with a first drive signal on columnelectrode 704A (applied to two touch nodes in the column of touch nodes)and can be driven with a second drive signal on column electrode 704B(e.g., applied to two different touch nodes in the column of touch nodesfor a 4×4 array). As shown in FIG. 7A, the first drive signal is appliedto alternating touch nodes in the column and the second drive signal isapplied to alternating touch nodes in the column.

Row electrodes can be differentially sensed using differentialamplifiers. Differentially sensing the row electrodes can remove commonmode noise from the touch measurements.

Although applying complimentary signals is shown in adjacent electrodesfor each column (e.g., the complementary signals D0/D0′ are applied tocolumn 1, the complementary signals D1/D1′ are applied to column 2,etc.), it is understood that the complimentary signal can be applied todifferent column electrodes such that the net electrical effect may bezero (or within a threshold of zero) over a larger localized region thetouch sensor panel (e.g., across diagonal touch nodes), but may not benet zero within a column of the touch sensor panel (e.g., for adjacenttouch nodes). In some examples, the cancelation of the complimentarysignals can occur on diagonal touch nodes, as described in more detailwith respect to FIGS. 13A-13B. For example, the drive circuitry can beconfigured to drive column electrode 704A with D0+, column electrode704B with D1−, column electrode 704C with D1+ and column electrode 704Dwith D0−. As a result, the cancelation of the transmit signals can occurat diagonals. For example, the cancelation of D0+ and D0− can occurbetween the transmitter electrode for the touch node in row 1, column 1of the array of FIG. 7A and the transmitter electrode for the touch nodeis row 2, column 2. In a similar manner, the cancelation of D1+ and D1−can occur between the transmitter electrode for the touch node in row 1,column 2 of the array of FIG. 7A and the transmitter electrode for thetouch node is row 2, column 1. In some examples, due to the increaseddistance along the diagonal, diagonal cancelation of the complementarydrive signals can result in increased sensed signal in response to atouching object (because there is less cancelation of signal) comparedwith the sensed signal for a touch sensor panel with cancelation ofcomplementary drive signals within a column of touch nodes.

It should be understood that although touch sensor panel 700 includes a3×3 array of nine dominant capacitance values (e.g., corresponding tonine effective touch nodes), that the touch sensor panel can be scaledup or down to include fewer or more touch nodes. For example, a touchsensor panel can be scaled to a 4×4 array of sixteen dominantcapacitance values (e.g., corresponding to sixteen effective touchnodes), or scaled to an 8×8 array of touch nodes (e.g., 64 capacitancevalues for 64 effective touch nodes) by increasing the row electrodes,column electrodes, drivers/transmitters and differential amplifiers.

Additionally, it should be understood that although differential drivingand sensing is described with reference to touch sensor panel 700 inFIG. 7A, that touch sensor panel 700 can, in some examples, be operatedin a non-differential sensing configuration to sense stimulation from aninput device (e.g., a stylus that provides stimulation) in contact orproximity to touch sensor panel 700. For example, in order to detect theinput device stimulation, switching circuitry can be used to couple thetwo row electrodes for a row of touch nodes to the same input of adifferential amplifier (e.g., inverting input), and couple another inputof the differential amplifier (e.g., non-inverting input) to a ground oranother reference potential (e.g., corresponding to the row electrodesbeing detected as one sense line using the touch circuitry in theconfiguration shown in FIG. 3B). In contrast, for differential drivingand sensing described herein, the switching circuitry can couple the rowelectrodes to differential amplifiers (e.g., as represented bydifferential amplifiers 708. For example, switching circuitry (notshown) can be optionally included between two routing traces for rowelectrodes 702A and 702B and corresponding differential amplifier 708.The switching circuitry can include one or more switches includingmultiplexer(s) and/or switch(es) that can be controlled by a modeselection input. In a differential drive/sense mode of operation, theswitching circuitry (can couple row electrode 702A to the non-invertingterminal (and can decouple row electrode 702A from the invertingterminal) and row electrode 702B can be coupled to the invertingterminal of differential amplifier 708. In a non-differential sensingconfiguration to sense stimulation from an input device (e.g., astylus), row electrode 702A and row electrode 702B can be coupled to theinverting terminal of differential amplifier 708 and the non-invertingterminal of differential amplifier 708 can be coupled to ground (or avirtual ground) using the switching circuitry. In some examples, for thenon-differential operation, the column electrodes in each column can usethe same phase stimulation signals rather than complimentary signals(e.g., D0 can be applied to column electrodes 704A-704B for the firstcolumn, D1 can be applied to column electrodes 704C-704D for the secondcolumn, etc.).

As shown in FIG. 7A, the column electrodes can be routed to drivecircuitry using column routing traces that are vertical (e.g., columnelectrodes 704A-704F routed to drivers, such as driver 706, usingvertical column routing traces 705A-705F). In some examples, the rowelectrodes can be routed to sensing circuitry using horizontal rowrowing traces (e.g., row electrodes 702A-702F routed to sensingcircuitry, such as differential amplifiers 708′, using horizontal columnrouting traces). In some examples, both the column electrodes and therow electrodes can be routed to drive circuitry or sensing circuitryusing vertical routing traces (e.g., using vertical column routingtraces 705A-705F and using vertical row routing traces 703-703F). Usingvertical routing traces for the row and column electrodes (or moregenerally routing the row and column electrodes to a same edge) canallow for routing the row and column electrodes to a common location(for connection to the drive circuitry and sensing circuitry) withoutrequiring vertical routing traces in the border area, thereby enablingthe device include touch sensor panel 700 to have reduced border.

FIG. 7A illustrates two vertical routing traces for complimentary drivesignals per column of column electrodes and two vertical routing tracesper row of row electrodes (e.g., two vertical routing traces per pair ofrow electrode). In some examples, additional routing traces can be usedfor rows and/or column electrodes. For example, rather than using onerouting electrode per drive signal per column (e.g., two total forcomplimentary drive signals applied to a column) multiple routing tracescan be used (e.g., four routing traces, two for each of thecomplimentary drive signals). In some examples, rather than using onerouting electrode per column (e.g., two total for a differentialamplifier for a row) multiple routing traces can be used. For example,FIGS. 7B-7C illustrate different configurations of routing traces for atouch node with two vertical routing traces for row electrodes and fourvertical routing traces for column electrodes according to examples ofthe disclosure.

FIG. 7B illustrates a first configuration 720 of routing traces for atouch node with two vertical routing traces for row electrodes and fourvertical routing traces for column electrodes. The touch node includes asegment of a row electrode 702 (e.g., with a shape of a rectangle withan “H” shaped cutout) and a segment of a column electrode 704 (e.g.,having a “H” shape). Configuration 720 includes two vertical routingtraces 726 and 728 used for routing complimentary drive signals for thecolumn in which the touch electrode of FIG. 7B is located. One of thevertical routing traces—routing trace 726 or routing trace 728—can beelectrically connected to the column electrode segment 704. In someexamples, column electrode segment 704 can be formed in second metallayer 506, the routing traces can be formed in the first metal layer516, and the electrical connection between the column electrode segment704 and the routing trace can be made with a via through theintermediate layer 507. In some examples, routing traces 726 and 728 canextend from one edge of the touch sensor panel to the opposite edge(e.g., from the top to the bottom). In some such examples, the routingtraces 726 and 728 make electrical connections with alternate columnelectrode segments in a column. For example, column electrode segmentsin the column can be connected to routing trace 726 for even rows of thetouch sensor panel and column electrode segments in the column can beconnected to routing trace 728 for odd rows of the touch sensor panel.

Configuration 720 also includes four vertical routing traces 730, 732,734 and 736 used for routing a row electrode 702 (including one or moresegments). One or more of the vertical routing traces—routing trace 730,732, 734 and/or 736—can be electrically connected to the row electrode702. As described in more detail herein, in some examples, a differentnumber of routing traces can be electrically connected to a respectiverow electrode 702 depending on the position of the respective rowrelative to the sensing circuitry. In some examples, the further arespective row electrode is from the sensing circuitry, the more routingtraces can be coupled to the respective row electrode. In some examples,the row electrode 702 can be formed in second metal layer 506, therouting traces can be formed in the first metal layer 516, and theelectrical connection between the row electrode 702 and the routingtrace can be made with one or more vias through the intermediate layer507. In some examples, routing traces 730, 732, 734 and/or 736 canextend from one edge of the touch sensor panel to the opposite edge(e.g., from the top to the bottom), optionally with some breaks orinterconnections, as described in more detail herein.

As shown in FIG. 7B, the vertical routing traces 726 and 728 for columnelectrodes can be disposed to overlap the arms of the H-shape columnelectrode segment (e.g., approximately at the middle of the arms) andthe vertical routing traces 730, 732, 734 and 736 for row electrodes canbe disposed on opposite sides of the vertical routing traces 726 and 728for column electrodes. For example, vertical routing traces 726 can besandwiched between the vertical routing traces 730 and 732 and verticalrouting traces 728 can be sandwiched between the vertical routing traces734 and 736. In some examples, vertical routing traces 726, 728, 730,732, 734 and 736 can be equally spaced. In some examples, verticalrouting traces 730 and 736 can be disposed so as not to overlap columnelectrode segment 704, whereas vertical routing traces 732 and 734 canpartially overlap column electrode segment 704, but between the arms soas to minimize the overlap of the vertical routing traces for rowelectrodes with the column electrode.

FIG. 7C illustrates a second configuration 740 of routing traces for atouch node with two vertical routing traces for row electrodes and fourvertical routing traces for column electrodes. Configuration 740 can besimilar to configuration 720, but have different placement of thevertical routing traces 746 and 748 for column electrodes (e.g.,corresponding to vertical routing traces 726 and 728) and verticalrouting traces 750, 752, 754, and 756 for row electrodes (e.g.,corresponding to vertical routing traces 730, 732, 734, and 736).

As shown in FIG. 7C, the vertical routing traces 746 and 748 for columnelectrodes can be disposed to overlap the arms of the H-shape columnelectrode segment (e.g., approximately at the outside edges of the arms)and the vertical routing traces 750, 752, 754 and 756 for row electrodescan be disposed on opposite sides of the vertical routing traces 746 and748 for column electrodes. For example, vertical routing traces 746 canbe sandwiched between the vertical routing traces 750 and 752 andvertical routing traces 748 can be sandwiched between the verticalrouting traces 754 and 756. In some examples, vertical routing traces746, 748, 750, 752, 754 and 756 can be equally spaced, with greaterspacing than in the configuration of FIG. 720 . In some examples,vertical routing traces 750 and 756 can be disposed so as not to overlapcolumn electrode segment 704 (e.g., at or within a threshold distance ofthe outer edge of the segment of the row electrode shown in FIG. 7B-7C),whereas vertical routing traces 752 and 754 can partially overlap columnelectrode segment 704, but between the arms so as to minimize theoverlap of the vertical routing traces for row electrodes with thecolumn electrode. In some examples, vertical routing traces 752 and 754can be at or within a threshold distance of the inner edge of the armsof the H-shaped column electrode segment 704.

Although described with reference to FIGS. 7B and 7C as vertical routingtraces 746, 748, 750, 752, 754 and 756, it should be understood thatthese vertical routing traces can represent routing tracks (e.g.,regions within the metal mesh) within which one or more routing tracescan be implemented for a column. The routing tracks are sometimesreferred to herein as a set of one or more routing trace segments, andelectrically connected portions of one or more sets of the one or morerouting traces segments can form a respective routing trace for arespective row electrode (or column electrode). In some examples, therouting tracks are simply referred to in shorthand as a routing trace inthat conceptually the various routing segments in a vertical routingtrack extend the full length or substantially the full length of acolumn, despite the possibility that different routing segments may beelectrically isolated from one another and may be used for routing morethan one row electrode (or may be floating).

FIGS. 8-10 illustrate different routing patterns for row electrodesaccording to examples of the disclosure. FIG. 8 illustrates a chevronrouting pattern according to examples of the disclosure. FIG. 8illustrates a touch sensor panel 800 that includes a 48×32 array oftouch nodes as indicated by the indexing on the left and top size of thearray, with each box in the array representing a touch node formed froma row electrode and column electrode segment (e.g. corresponding totouch nodes shown in FIGS. 7A-7C). Each of the rows can include two rowelectrodes, for a total of 96 row electrodes to be routed to the sensingcircuitry (e.g., to differential amplifiers). Touch sensor panel 800 canbe divided into three banks, with each bank including 16 rows. Forexample, a first bank 802 can include rows 1-16, a second bank 804 caninclude rows 17-32, and a third bank 806 can include rows 33-48. Itshould be understood that a touch sensor panel can include a differentsize array or different number of banks than shown in FIG. 8 .

Touch sensor panel 800 includes vertical routing tracks for rowelectrodes in groups 808 of four vertical routing tracks per column.Electrical connections between one or more of the routing tracesimplemented with the vertical routing tracks are indicated at touchnodes with a numerical text label (“1”, “2:1”, or “4:2”). A group 808 offour vertical routing tracks in one column of the touch sensor panel canbe used to make electrical connections to one row electrode per bank(e.g., using three routing traces implemented within the four routingtracks). For example, the leftmost group 808 can be used to makeelectrical connections to a row electrode in rows 2, 18 and 34 in banks802, 804 and 806 respectively as indicated by touch nodes with numericaltext labels (“1”, “2:1”, or “4:2”). For each column in the chevronrouting pattern, the location of the electrical connection for the rowsin different banks can be equally spaced. For example, the connectionsin column 1 (at rows 2, 18 and 34) can be 16 rows apart, and that samespacing between connections can repeat for each of the columns in thechevron routing pattern of FIG. 8 . This spacing can help balancebandwidth for the touch sensor panel because the uniform spacing canhelp equalize the resistance for the routing traces across the touchsensor panel. Although not shown in FIG. 8 for ease of illustration,each column of the touch sensor panel can include two vertical routingtraces (and two vertical routing tracks) for routing column electrodesegments to the drive circuitry.

For ease of illustration, FIG. 8 shows the groups 808 of four verticalrouting tracks for odd-numbered columns, representing one of a pair ofrow electrodes in a row of the touch sensor panel (e.g., to be coupledto one terminal of a differential amplifier for the row or otherwisecoupled to one terminal of an amplifier for a differential measurement),but it is understood that similar groups of vertical routing tracks canbe used for even-numbered columns to make electrical connections to theother of the pair of row electrodes in a row of the touch sensor panel(e.g., to be coupled to the other terminal of the differential amplifierfor the row). For example, vertical routing tracks of group 808 incolumn 1 can be used to make electrical connections to one of the rowelectrode in rows 2, 18 and 34 of the touch sensor panel, and anothergroup of vertical routing tracks in adjacent column 2 can be used tomake electrical connections to the other of the row electrodes in rows2, 18 and 24. Thus, each bank can include one electrical connection percolumn for a total of 32 electrical connections per bank, and 96electrical connections for the three banks.

Although described above as having the second row electrode for a rowbeing electrically connected in the adjacent column, it is understoodthat in some examples, the connection for the second row electrode for arow can be made in a different column. For example, the connection forthe even-numbered columns can occur at the touch nodes on the diagonalbetween two odd-numbered columns. For example, the electrical connectionfor one row electrode in row 48 can be made in column 15 and theelectrical connection for the second row electrode in row 48 can be madein column 16; the electrical connection for one row electrode in row 47can be made in column 17 and the electrical connection for the secondrow electrode in row 47 can be made in column 14; the electricalconnection for one row electrode in row 46 can be made in column 13 andthe electrical connection for the second row electrode in row 46 can bemade in column 18; the electrical connection for one row electrode inrow 45 can be made in column 19 and the electrical connection for thesecond row electrode in row 45 can be made in column 12, and so on.

As illustrated in FIG. 8 , touch sensor panel 800 can have a chevronrouting pattern because the locations of the electrical connections foreach bank result in a chevron shaped pattern. For example, theelectrical connections between routing traces and row electrodes for abank can be positioned in an increasing slope arrangement when movingtoward the center of the bank, and positioned in a decreasing slopearrangement when moving toward the left and right edges from the centerof the bank. In some examples, the electrical connections on the lefthalf of the bank can be for even rows, and those connections on theright half of the bank can be for odd rows (vice versa). For example,for bank 806, the electrical connections for rows can occur at thosetouch nodes labeled “4:2.” The chevron pattern can point upward in FIG.8 such that the electrical connections for row 48 at the top of bank 806can be at the center of the 32 rows (e.g., at columns 15 and 16). Thechevron pattern repeats in a similar manner for banks 802 and 804.

In some examples, having the chevron pattern point upward can helpreduce the maximum length of a routing trace and therefore the maximumresistance. For example, the vertical routing traces can be routed to acenter region 850 at the bottom of the panel (e.g., in a border regionoutside the active area of the touch sensor panel). The center region850 can be a group of bond pads or other connections to enableconnection to a touch sensing circuit including the differentialamplifiers (or single-ended amplifier configured for differentialmeasurements). As a result, groups 808 of routing track and routingtraces implemented within the routing tracks at the left-most andright-most edges of the touch sensor panel can travel a greaterhorizontal distance to center region 850 (e.g., in the bottom borderregion) compared with a group of routing traces in the center of thetouch sensor panel. To balance these trace lengths, the upward pointingchevron pattern can allow for routing traces in a group of routingtracks to travel a shorter vertical distance for the left-most andright-most edges of the touch sensor panel compared with routing tracesin a group of routing tracks in the center of the touch sensor panel. Asa result, the upward facing chevron pattern can reduce the maximum pathlength and thereby reduce the maximum routing trace resistance toincrease the bandwidth of touch sensor panel 800. It should beunderstood, however, that in some examples, the chevrons may be orienteddifferently (e.g., pointing downward).

As shown in FIG. 8 , the vertical routing tracks can extendsubstantially from one edge of the touch sensor panel (e.g., a bottomedge) to an opposite edge (e.g., a top edge) for improved opticalperformance. For example, rather than terminating a vertical routingtrace withing a vertical routing track at the point of an electricalconnection with a row electrode, the vertical routing track can includerouting trace segments that can extend beyond the point of an electricalconnection so that the vertical routing track may provide a more uniformpattern of metal mesh wire that may be less visible to a user (forimproved optical performance). In some examples, the vertical routingtracks may include one or more breaks (e.g., discontinuities in themetal mesh) so that the remainder of the routing traces segment(s) in avertical routing track beyond the touch node at which an electricalconnection is made is not electrically connected to the sensingamplifier (e.g., floating or tied to a voltage potential). For example,FIG. 8 shows a break 813 in the metal mesh of a vertical routing trackafter vertical routing trace 810D makes an electrical connection to rowelectrode 814A, a break 823 in the metal mesh of two vertical routingtracks after vertical routing trace 810C makes an electrical connectionto row electrode 814B, and a break 833 in the metal mesh of fourvertical routing tracks after vertical routing traces 810A and 810B makeelectrical connection(s) to row electrode 814C. The breaks in the metalmesh beyond the electrical connection can de-load the traces.

Additionally, or alternatively, as explained in more detail below, insome examples, the effective resistance of routing can be different fordifferent banks of the touch sensor panel 800. For example, after aportion of a routing trace electrically connected to a row electrode(and after a break in the routing track), some or all of the remainderof the routing trace segments within the routing track can be repurposedand interconnected to one or more of the remaining routing tracesegments within one or more other routing tracks to increase theeffective width of the routing trace and thereby reduce the effectiveresistance of the routing trace for routing traces connecting to touchnodes in the downstream banks. In this way, disconnections (breaks) andinterconnections of the group of vertical routing tracks can be used tobalance bandwidth for the touch sensor panel. In some examples, therouting trace utilization (the disconnections and interconnections ofthe vertical routing tracks) can be optimized on a per touch-node basisto reduce the maximum routing trace resistance or to reduce the variancein the total routing trace resistance.

For example, a first routing trace can include a portion (e.g., verticalrouting trace 810D) of a first vertical routing track, and can be usedto route a row electrode 814A in row 1, column 31 to the bottom of touchsensor panel 800. The electrical connection can be made by one or morevias 812 between the row electrode and the first routing trace (e.g.,vertical routing trace 810D) at the location of row electrode 814A inthe touch node at row 1, column 31. After a break 813, some or all ofthe remaining portions of the vertical routing track (represented byrouting trace segments 810D′, 810D″, and 810D″), can be used forreducing the routing trace resistance for upstream banks. For example, asecond routing trace can include a second portion (e.g., routing tracesegment 810D′) of the first vertical routing track and a portion (e.g.,routing trace 810C of a second vertical routing track). For example,segments of the first and second routing tracks can be coupled and oneor more points between the electrical connection at row 1, column 31 (inbank 802) and the electrical connection at row 17, column 31 (in bank804) to double the effective width (and thereby reduce the resistance)for the second routing trace between row 2 and 17 as compared with thewidth of the second routing trace between rows 1 and 2. The electricalconnection can be made by one or more vias 822 between the row electrodeand the second routing trace (e.g., with vertical routing trace 810Cand/or interconnected trace segment 810D′) at the location of rowelectrode 814B in the touch node at row 17, column 31.

After a break 823, some or all of the remaining portions of the firstand second vertical routing tracks (represented by routing tracesegments 810C′, 810D″, and 810D″), can be used for reducing the routingtrace resistance for the upstream bank. For example, a third routingtrace can include a portion (e.g., vertical routing traces 810A and810B) of a third vertical routing track and a fourth vertical routingtrack, a third portion of the first vertical routing track and a secondportion of the second routing track. For example, segments of the thirdand fourth routing tracks can be interconnected at one or more pointsbetween the electrical connection to row electrode 814C and thedifferential amplifier circuit (e.g., in or outside of the active areaof the touch sensor panel). Additionally, routing trace segments 810C′and 810D″ in the first and second routing tracks can be coupled tovertical routing traces 810A and 810B at one or more points between theelectrical connection at row 17, column 31 (in bank 804) and theelectrical connection at row 33, column 31 (in bank 806) to double theeffective width (and thereby reduce the resistance) of the third routingtrace between rows 18 and 33 compared with the width of the thirdrouting trace between rows 1 and 18 (and quadruple the effective widthcompared to a single vertical routing track) for the routing tracesbetween rows 17 and 33. The electrical connection can be made by one ormore vias 832 between the row electrode and the third routing trace(e.g., with vertical routing traces 810A-810B and/or interconnectedrouting trace segments 810C′ and 810D″) at the location of row electrode814C in the touch node at row 33, column 31. After a break 833, theremaining routing segments 810A′, 810B′, 810C″ and 810D′″ can bedecoupled for the routing traces and from the differential amplifiers.

The numerical text labels for the touch nodes with electricalconnections provide an indication regarding the number of verticalrouting tracks used for each routing trace and the effective width ofthe routing traces used for routing to the row electrode in each bank.For example, the numerical text label “1” for touch nodes with anelectrical connection indicates that a portion of one of the fourvertical routing tracks in a group 808 (with an effective width of onerouting track) can be used for a routing trace (e.g., like the firstrouting trace including routing trace segment 810D). The numerical textlabel “2:1” for touch nodes with an electrical connection indicates thata portion of two of the four vertical routing tracks in a group 808 canbe used to double the effective width for a portion of the routinglength (e.g., second routing trace including routing trace segment 810Cand interconnected routing trace segment 810D′). The numerical textlabel “4:2” for touch nodes with an electrical connection indicates thatportions of the four vertical routing traces in a group 808 can be usedto double the effective width for a portion of the routing length (e.g.,third routing trace including routing trace segments 810A-810B andinterconnected routing trace segments 810C′ and 810D″).

Alternatively, the numerical text label “2:1” can provide an indicationof a transition point between an effective width of two routing tracksto an effective width of one routing track and the numerical text label“4:2” can provide an indication of a transition point between aneffective width of four routing tracks to an effective width of tworouting tracks.

It should be understood that the dimensions of the touch sensor panel,the number of banks, and the number of vertical routing tracks per groupare exemplary. In some examples, the touch sensor panel can be doubledin size by to have 48 rows and 64 columns, and the chevron pattern shownin FIG. 8 can repeat for columns 33-64. In some such examples, each rowcan have two row electrodes, and the additional columns can be used todouble the number of routing traces used to make an electricalconnection. In some such examples, each row can have four rowelectrodes. For example, two row electrodes per row can be used forcolumns 1-32 and an additional two row electrodes per row can be usedfor columns 33-64. In some examples, more or fewer vertical routingtracks or banks can be used than shown in FIG. 8 .

The chevron routing pattern can be used to maximize bandwidth for thetouch sensor panel by reducing a maximum total routing trace length.However, in some examples, because routing for adjacent rows can beseparated by a large number of columns. For example, the electricalconnection for row 36 (at column 3) and row 35 (at column 29) can beseparated by 26 columns and the electrical connection for row 32 (atcolumn 15) and row 33 (at column 31) can be separated by 16 columns. Incontrast, the electrical connection for row 48 (at column 15) and row 47(at column 17) can be separated by 2 columns. As a result, the touchnodes of touch sensor panel 800 may have resistance differentialsbetween adjacent touch nodes that can result in reduced accuracy formeasuring a location of an object moving across the touch sensor panel.In some examples, the reduced accuracy can manifest in increased wobblefor an active or passive stylus input device due to the resistancedifferential between adjacent touch nodes in a column (and/or in a row).

FIG. 9 illustrates an S-shaped or zig-zag routing pattern according toexamples of the disclosure. The S-shaped routing pattern can reduce theresistance differential between adjacent touch nodes in a column (and/orin a row) compared with the chevron routing pattern illustrated in FIG.8 , but with a reduction in the bandwidth of the touch sensor panel dueto a longer maximum routing trace resistance (e.g., a reduction inbandwidth between 5%-25%). FIG. 9 illustrates a touch sensor panel 900that includes a 48×32 array of touch nodes similar to that of touchsensor panel 800, that can include banks 902, 904 and 906 (e.g.,corresponding to banks 802, 804, and 806), but including a differentpattern of electrical connections between the groups 908 of verticalrouting tracks (e.g., corresponding to groups 808 of four verticalrouting tracks).

Electrical connections between one or more of the row electrodes androuting traces using segments in the vertical routing tracks areindicated at touch nodes with a numerical text label (“1”, “2:1”, “2” or“4:2”). A group 908 of four vertical routing tracks in one column of thetouch sensor panel can be used to make electrical connections to one rowelectrode per bank. For example, the leftmost group 908 can be used tomake electrical connections to a row electrode in rows 1, 32 and 33 inbanks 902, 904 and 906 respectively as indicated by touch nodes withnumerical text labels (“1”, “2:1”, or “2”). Unlike the chevron routingpattern, the location of the electrical connection for the rows indifferent banks may not be equally spaced. For example, the connectionsin column 1 (at rows 1, 32 and 33), some of the connections can be 31rows apart and other connections can be at adjacent rows, and thedisparate spacing between connections can cause a decrease in bandwidthfor the touch sensor panel due to non-uniform spacing and increasedtrace resistances for some of the routing traces of the touch sensorpanel. Although not shown in FIG. 9 for ease of illustration, eachcolumn of the touch sensor panel can include two vertical routing tracksfor routing column electrode segments to the drive circuitry.

For ease of illustration, FIG. 9 shows the groups 908 of four verticalrouting tracks for odd-numbered columns, representing one of a pair ofrow electrodes in a row of the touch sensor panel (e.g., to be coupledto one terminal of a differential amplifier for the row), but it isunderstood that similar groups of vertical routing tracks can be usedfor even-numbered columns to make electrical connections to the other ofthe pair of row electrodes in a row of the touch sensor panel (e.g., tobe coupled to the other terminal of the differential amplifier for therow). For example, vertical routing tracks of group 908 in column 1 canbe used to make electrical connections to one of the row electrode inrows 1, 32 and 33 of the touch sensor panel, and another group ofvertical routing tracks in adjacent column 2 can be used to makeelectrical connections to the other of the row electrodes in rows 1, 32and 33. Thus, each bank can include one electrical connection per columnfor a total of 32 electrical connections per bank, and 96 electricalconnections for the three banks. Although described above as having thesecond row electrode for a row being electrically connected in theadjacent column, it is understood that, in some examples, the connectionfor the second row electrode for a row can be made in a differentcolumn.

As illustrated in FIG. 9 , touch sensor panel 900 can be said to have anS-shaped routing pattern because the locations of the electricalconnections for each bank result in an S-shaped shaped pattern. Forexample, the electrical connections between routing traces and rowelectrodes for a bank can be positioned in a single slope arrangementbetween left and right edges of the bank. In some examples, adjacentbanks (e.g., vertically adjacent) can have their electrical connectionsbe arranged in opposite slopes (alternating from left to right or fromright to left). Additionally, the electrical connections for the twoadjacent rows at a boundary between two adjacent banks (e.g., anelectronical connection between a first row in a first bank and anelectrical connection between a second row in a second bank differentthan the first bank, the first row and the second row being adjacent)can be adjacent to one another (near a common edge of the touch sensorpanel). For example, each sequential electrical connections between abottom row of a first bank and a top row of an adjacent second bank canbe located along a common edge of the touch sensor panel (e.g., along aright edge or a left edge). For example, for bank 906, the electricalconnections for rows can occur at those touch nodes labeled “4:2” alonga first diagonal descending from row 48, column 32 to row 33, column 1.The S-shaped pattern repeats in a similar manner for banks 902 and 904,with electrical connections along a second diagonal descending from row32, column 1 to row 17 column 32 and along a third diagonal descendingfrom row 16, column 32 to row 1, column 1. The electrical connectionsfor row 33, column 1 and row 32, column 1 can be along the left edge ofthe touch sensor panel, and the electrical connections for row 17,column 32 and row 16, column 32 can be along the right edge of the touchsensor panel.

In some examples, having the S-shaped pattern can help reduce the changein resistance between adjacent rows and therefore reduce the row-to-rowchange in bandwidth. For example, the routing traces length and therebythe change in resistance for any two adjacent rows can be relativelysmall (e.g., less than 1000), whereas the chevron configuration of FIG.8 may have some discontinuities in which the routing trace length andthereby the change in resistance can be relatively greater between someadjacent rows (e.g., greater than 5000). For example, in the chevronconfiguration of FIG. 8 , the connections for row 32 and row 33 canoccur in column 15 and column 1, respectively, which can result in arelatively large different in trace length and resistance. In someexamples, reducing the row-to-row change in resistance can improveaccuracy for touch sensing that can manifest in decreased wobble for anactive or passive stylus input device due to the smaller resistancedifferential between adjacent touch nodes in a column (and/or in a row).

As shown in FIG. 9 , the vertical routing tracks (and the trace segmentstherein) can extend substantially from one edge of the touch sensorpanel (e.g., a bottom edge) to an opposite edge (e.g., a top edge) forimproved optical performance. For example, rather than terminating avertical routing trace at the point of an electrical connection with arow electrode, the segments in a vertical routing track can extendbeyond the point of an electrical connection so that the verticalrouting tracks may provide a more uniform pattern of metal mesh wirethat may be less visible to a user (for improved optical performance).In some examples, the vertical routing tracks may include breaks so thatthe remainder of a vertical routing track beyond the touch node at whichan electrical connection is made is not electrically connected to thesensing amplifier (e.g., floating or tied to a voltage potential), asdescribed above with reference to FIG. 8 and not repeated here forbrevity.

Additionally, or alternatively, as explained above with respect to FIG.8 , in some examples, the effective resistance of routing can bedifferent for different banks of the touch sensor panel 900. Forexample, after a routing trace including a portion of a routing trackelectrically connects to a row electrode (and after a break in therouting track), some or all of the remainder of the routing track berepurposed and/or interconnected to one or more of the remaining routingtraces to increase the effective width of the routing trace and therebyreduce the effective resistance of the routing trace for routing tracesconnecting to touch nodes in the downstream banks. In this way,disconnections (breaks) and interconnections of the group of verticalrouting tracks can be used to better balance bandwidth for the touchsensor panel. In some examples, the routing track utilization (thedisconnections and interconnections of the vertical routing tracks) canbe optimized on a per touch-node basis to reduce the maximum routingtrace resistance or to reduce the variance in the total routing traceresistance.

It should be understood that the dimensions of the touch sensor panel,the number of banks, and the number of vertical routing tracks per groupare exemplary. In some examples, the touch sensor panel can be doubledin size by to have 48 rows and 64 columns, and the S-shaped patternshown in FIG. 9 can repeat for columns 33-64 (e.g., mirrored across theboundary between columns 32 and 33). In some such examples, each row canhave two row electrodes, and the additional columns can be used todouble the number of routing traces used to make an electricalconnection. In some such examples, each row can have four rowelectrodes. For example, two row electrodes per row can be used forcolumns 1-32 and an additional two row electrodes per row can be usedfor columns 33-64. In some examples, more or fewer vertical routingtracks or banks can be used than shown in FIG. 9 .

In some examples, a hybrid routing pattern can be used. In a hybridrouting pattern some routing traces are disposed in the active area(e.g., overlapping row and/or column electrodes) and some routing tracesare disposed outside the active area (e.g., in a border area). FIG. 10illustrates hybrid routing pattern according to examples of thedisclosure. The hybrid routing pattern can include features of theS-shaped or zig-zag routing pattern illustrated in FIG. 9 (e.g., rowconnections along a diagonal), but also includes some border-arearouting traces. The hybrid routing pattern can reduce the resistancedifferential between adjacent touch nodes in a column (and/or in a row)in a similar manner as described above with respect to FIG. 9 . However,the use of border-area routing traces can reduce the number of routingtracks required in the active area and/or reduce the maximum resistanceof routing traces by repurposing more of the routing tracks for thelonger routing traces.

FIG. 10 illustrates a touch sensor panel 1000 that includes a 48×32array of touch nodes similar to that of touch sensor panel 900, that caninclude banks 1002, 1004 and 1006 (e.g., corresponding to banks 902,904, and 906), but including a different pattern of electricalconnections between the groups 1008 of vertical routing tracks (e.g.,groups of two vertical routing tracks). Although two vertical routingtracks are shown per column, these routing tracks can be thicker (andtherefore have improved resistance characteristics (e.g., reducedresistance per unit length of the routing trace)). Alternatively, thevertical routing tracks can include four vertical routing tracks (e.g.,corresponding to groups 908 of four vertical routing tracks), where twoof four vertical routing tracks can be routed with the same connectionsas one of the two illustrated vertical routing traces in FIG. 10 (oralternatively, some or all of the columns can use one of the fourvertical routing tracks for interconnections in the first bank 1002 andthree of the four vertical routing tracks for interconnections to thethird bank 1006).

Electrical connections between one or more of the row electrodes androuting traces using segments in the vertical routing tracks areindicated at touch nodes with a numerical text label (“1” or “2:1”). Agroup 1008 of two vertical routing tracks in one column of the touchsensor panel can be used to make electrical connections to one rowelectrode in an upper bank and one row electrode in a lower bank. Forexample, the leftmost group 1008 can be used to make electricalconnections to a row electrode in rows 16 and 33 in banks 1002 and 1006,respectively, as indicated by touch nodes with numerical text labels(“1” or “2:1”). In a similar manner, in vertical routing tracks incolumn 3 can be used to make electrical connections to a row electrodein rows 15 and 34 in banks 1002 and 1006. The electrical connection toeach of the row electrodes in the middle bank 1004 can be made using arouting trace (e.g., routing trace 1010) in the border area (e.g.,outside the active area). The routing traces in the border area may alsobe referred to herein as a border-area routing trace or a border routingtrace. Like the routing S-shaped routing pattern of FIG. 9 , thelocation of the electrical connection for the rows in different banksmay not be equally spaced. For example, the connections in column 1 (atrows 16 and 33), the connections can be 17 rows apart and theconnections in column 31 can be 47 rows apart. The disparate spacingbetween connections can cause a decrease in bandwidth for the touchsensor panel due to non-uniform spacing and increased trace resistancesfor some of the routing traces of the touch sensor panel. In someexamples, as described herein, the increased trace resistances can bereduced using the hybrid routing configuration. Although not shown inFIG. 10 for ease of illustration, each column of the touch sensor panelcan include two vertical routing tracks for routing column electrodesegments to the drive circuitry.

For ease of illustration, FIG. 10 shows the groups 1008 of two verticalrouting tracks for odd-numbered columns, representing one of a pair ofrow electrodes in a row of the touch sensor panel (e.g., to be coupledto one terminal of a differential amplifier for the row), but it isunderstood that similar groups of vertical routing tracks can be usedfor even-numbered columns to make electrical connections to the other ofthe pair of row electrodes in a row of the touch sensor panel (e.g., tobe coupled to the other terminal of the differential amplifier for therow). For example, vertical routing tracks of group 1008 in column 1 canbe used to make electrical connections to one of the row electrode inrows 1 and 33 of the touch sensor panel, and another group of verticalrouting tracks in adjacent column 2 can be used to make electricalconnections to the other of the row electrodes in rows 1 and 33. Theelectrical connections for the pair of row electrodes can be made in theborder area (e.g., on the same side or on opposite sides of the touchsensor panel). Thus, each of the upper bank and the lower bank caninclude one electrical connection per column and the middle bank caninclude two electrical connections per row (one each for the pair of rowelectrodes in a row) for a total of 32 electrical connections per bank,and 96 electrical connections for the three banks. Although describedabove as having the second row electrode for a row being electricallyconnected in the adjacent column in the upper and lower banks, it isunderstood that, in some examples, the connection for the second rowelectrode for a row can be made in a different column.

As illustrated in FIG. 10 , touch sensor panel 1000 can have routingpattern similar to the S-shaped routing pattern. For example, theelectrical connections between routing traces and row electrodes for abank can be positioned in a single slope arrangement between left andright edges of the bank. For example, for bank 1006, the electricalconnections for rows can occur at those touch nodes labeled “2:1” alonga first diagonal descending from row 48, column 32 to row 33, column 1.The electrical connections for bank 1002 follow in a similar manner,with electrical connections along a second diagonal descending from row16, column 1 to row 1, column 32. The intermediate bank 1004 can beconnected using border area routing, as described herein. In someexamples, the first and third banks separated by the intermediate bankcan have their electrical connections be arranged in opposite slopes(alternating from left to right or from right to left). Additionally, anelectronical connection between a first row in a first bank adjacent toa row connected using border-area routing and an electrical connectionbetween a second row in a second bank different than the first bank canbe at or near a common edge of the touch sensor panel. For example, theelectrical connections for row 33, column 1 and row 16, column 1 can bealong the left edge of the touch sensor panel.

In some examples, having the diagonal pattern similar to the S-shapedpattern in the hybrid device can help reduce the change in resistancebetween adjacent rows within the upper and lower banks and thereforereduce the row-to-row change in bandwidth. In some examples, theborder-area routing traces can also be designed to reduce the row-to-rowchange in resistance and provide relative continuity in resistance forthe middle bank (e.g., between the resistance in the top row of thelower bank and the bottom row of the upper bank).

As shown in FIG. 10 , the vertical routing tracks (and the tracesegments therein) can extend substantially from one edge of the touchsensor panel (e.g., a bottom edge) to an opposite edge (e.g., a topedge) for improved optical performance. For example, rather thanterminating a vertical routing trace at the point of an electricalconnection with a row electrode, the vertical routing track can extendbeyond the point of an electrical connection so that the verticalrouting tracks may provide a more uniform pattern of metal mesh wirethat may be less visible to a user (for improved optical performance).In some examples, the vertical routing tracks may include breaks so thatthe remainder of a vertical routing track beyond the touch node at whichan electrical connection is made is not electrically connected to thesensing amplifier (e.g., floating or tied to a voltage potential), asdescribed above with reference to FIG. 8 and not repeated here forbrevity.

Additionally, or alternatively, as explained above with respect to FIG.8 , in some examples, the effective resistance of routing can bedifferent for different banks of the touch sensor panel 1000. Forexample, after a routing trace including a portion of a routing trackelectrically connects to a row electrode (and after a break in therouting track), some or all of the remainder of the routing track berepurposed and/or interconnected to one or more of the remaining routingtraces to increase the effective width of the routing trace and therebyreduce the effective resistance of the routing trace for routing tracesconnecting to touch nodes in the downstream banks. In this way,disconnections (breaks) and interconnections of the group of verticalrouting tracks can be used to better balance bandwidth for the touchsensor panel. In some examples, the routing track utilization (thedisconnections and interconnections of the vertical routing tracks) canbe optimized on a per touch-node basis to reduce the maximum routingtrace resistance or to reduce the variance in the total routing traceresistance.

It should be understood that the dimensions of the touch sensor panel,the number of banks, and the number of vertical routing tracks per groupare exemplary. In some examples, the touch sensor panel can be doubledin size by to have 48 rows and 64 columns, and the hybrid pattern shownin FIG. 10 can repeat for columns 33-64 (e.g., mirrored across theboundary between columns 32 and 33). In some such examples, each row canhave two row electrodes, and the additional columns can be used todouble the number of routing traces used to make an electricalconnection. In some such examples, each row can have four rowelectrodes. For example, two row electrodes per row can be used forcolumns 1-32 and an additional two row electrodes per row can be usedfor columns 33-64. In some examples, more or fewer vertical routingtraces or banks can be used than shown in FIG. 10 .

Although FIG. 10 shows the upper and lower banks 1002 and 1006 withrouting traces in the active area and middle bank 1004 with routingtraces in the border area, it is understood that the distribution oftraces in the active area and in the border area can be different thanshown in FIG. 10 . For example, more or fewer of the electricalconnections can be changed between the S-shaped pattern and the hybridpattern (e.g., adding a partial third diagonal in the second bank byincluding some active area routing traces/tracks for the rows in themiddle bank or reducing the length of the diagonal in the upper and/orlower bank by using more border routing traces for electricalconnection).

As described herein, in some examples, the electrical connections for arow to a differential sense amplifier can impact cross-talk betweenadjacent rows within a column. FIGS. 11A-11B illustrate an example touchsensor with vertical routing traces and corresponding signal levels withand without cross-talk according to examples of the disclosure. FIG. 11Aillustrates a touch sensor panel 1100, which can correspond to the rowand column electrodes of touch sensor panel 700 (but with differentrouting shown). Row electrode 1104 corresponding to the touch node atrow 1, column 2 can be coupled to a sense amplifier using a routingtrace implemented with segments in three routing tracks 1106 (with threerouting trace connection points, such as vias, shown for row electrode1104). The routing tracks 1106 can be vertical routing tracks thatoverlap with other touch nodes in the column (e.g., at row 2, column 2and row 3, column 2). FIG. 11B illustrates a comparison of signalmeasurements at the touch electrodes in the second column with crosstalkand without cross-talk (e.g., actual or ideal signal) due to thepresence of a finger 1102 finger touching or in proximity to the touchnode at row 2, column 2. As shown in FIG. 11B, the presence of thefinger 1102 in proximity to routing traces 1106 at row 2, column 2 cancause modulation of the measured signal at row 1, column 2. In someexamples, the modulation can be on the order of 5%-30% depending on thesize, number, and/or orientation of finger(s). This modulation can causea distortion in the touch signal profile that results in inaccuratelocation detection and poorer touch performance. In some examples, asdescribed with respect to FIG. 11D, differential routing traces can beused to mitigate the impact of cross-talk.

FIG. 11C and FIG. 11D illustrate portions of example touch sensor panelswith non-differential routing traces or with differential routing tracesaccording to examples of the disclosure. The respective portions of thetouch sensor panel 1120 and 1140 each include a two-by-two array oftouch nodes including four column electrodes 1124A-1124D (H-shapedelectrodes) and four row electrodes labeled 1122A-1122D. The rowelectrodes 1122A-1122D can be routed to the sensing circuitry (e.g.,single-ended or differential amplifiers) using routing traces1126A-1126H. Electrical connections between the routing tracesimplemented in routing tracks 1126A-1126H and the row electrodes1122A-1122D can be made using vias 1128A-1128L. For simplicity columnrouting is not shown in FIGS. 11C-11D. The four row electrodes can becoupled to four inputs of the sensing circuitry, referenced with labelsS0+, S0, S1+, and S1− (e.g., which may be used for two differentialmeasurement). Two row electrodes 1122A and 1122B (also labeled S0+ andS0−) can be routed to two inputs of the sensing circuitry (e.g., twoterminals of a differential sense amplifier S0) for a differentialmeasurement, and two row electrodes 1122C and 1122D (also labeled S1+and S1−) can be routed to two inputs of the sensing circuitry (e.g., twoterminals of a differential sense amplifier S1) for a differentialmeasurement.

In some examples, as shown in non-differential configuration of FIG.11C, the routing traces for a first input of a differential measurementcan be disposed in one column and the routing traces for a second inputof the differential measurement can be disposed in a second column. Forexample, a first routing trace can be implemented using routing tracesegments in routing tracks 1126A and 1126B and using portions of routingtrace segments in routing tracks 1126C and 1126D. The first routingtrace can be electrically connected to row electrode 1122A using vias1128A-1128D and can be routed vertically in the left column. Routingtracks 1126A and 1126B also overlap row electrode 1122C, but withoutelectrical connection. In a similar manner, a second routing trace canbe implemented using routing trace segments in routing tracks 1126E and1126F and using portions of routing trace segments in routing tracks1126G and 1126H. The second routing trace can be electrically connectedto row electrode 1122B using vias 1128E-1128H and can be routedvertically in the right column. Routing tracks 1126E and 1126F alsooverlap row electrode 1122D, but without electrical connection. Itshould be understood that the routing for row electrodes 1122A and 1122Bcan correspond to two routing traces with a “4:2” electrical connectionthat includes a transition from using two vertical routing tracks tofour vertical routing tracks (e.g., to double the effective width for aportion of the routing length and thereby reduce routing traceresistance). For example, routing trace segments in routing tracks 1126Aand 1126B corresponding to one input of the sensing circuitry are shownto be connected and splitting into routing trace segments in four tracksover row electrode 1122A (e.g., with some horizontal interconnectionbetween the tracks near the border between row electrode 1122A and rowelectrode 1122C). Likewise, routing trace segments in routing tracks1126E and 1126F corresponding to another input of the sensing circuitryare shown to be connected and splitting into routing trace segments infour tracks over row electrode 1122B (e.g., with some horizontalinterconnection between the tracks near the border between row electrode1122B and row electrode 1122D). FIG. 11C also illustrates routing tracesegments in routing tracks 1126C and 1126D that are electricallyconnected to row electrode 1122C using vias 11281 and 1128) and routingtrace segments in routing tracks 1126G and 1126H that are electricallyconnected to row electrode 1122D using vias 1128K and 1128L. Asdescribed with reference to FIGS. 11A-11B, a finger touching or inproximity to the bottom right touch node including column electrode1124C and row electrode 1122C can cause some cross-talk (e.g.,modulation that distorts the touch signal) to be introduced in themeasurement of the top right touch node including column electrode 1124Aand row electrode 1122A due to the routing tracks 1126A and 1126Boverlapping the bottom right touch node.

In some examples, the cross-talk can be mitigated using differentialrouting traces as illustrated in FIG. 11D. In the differential routingconfiguration, the routing traces for a first input of a differentialmeasurement and the routing traces for a second input of thedifferential measurement can be disposed in the same column. Forexample, a first routing trace can be implemented using routing tracesegments in routing tracks 1126A and 1126B and using portions of routingtrace segments in routing tracks 1126C and 1126D, and a second routingtrace can be implemented using routing trace segments in routing tracks1126E and 1126F and using portions of routing trace segments in routingtracks 1126G and 1126H. The first routing trace is electricallyconnected to row electrode 1122A using vias 1128A-1128D and the secondelectrode is electrically connected to row electrode 1122B using vias1128E-1128H. The segments of the first and second routing traces can berouted vertically in pairs of routing tracks (e.g., in left column, andalso in the upper half of the right column). The first and secondrouting traces in routing tracks 1126A, 1126B, 1126E and 1126F alsooverlap row electrode 1122C, but without electrical connection. FIG. 11Dalso illustrates routing trace segments in routing tracks 1126C and1126D that are electrically connected to row electrode 1122C using vias11281 and 1128) and routing trace segments in routing tracks 1126G and1126H that are electrically connected to row electrode 1122D using vias1128K and 1128L. These segments can be routed vertically in pairs ofrouting tracks (e.g., in bottom right column), and these connections forrow electrodes 1122C and 1122D can be made within the same column (e.g.,rather than in different column as in FIG. 11C).

A finger touching or in proximity to the bottom left touch nodeincluding column electrode 1124C and row electrode 1122C can causemodulation to be introduced in the measurement of the top left touchnode including column electrode 1124A and row electrode 1122A due torouting tracks 1126A and 1126B overlapping the bottom left touch node.However, the same (or similar) modulation can be introduced in due tooverlapping routing tracks 1126E and 1126F overlapping the bottom lefttouch node. Thus a differential measurement of the inputs received fromthe first and second routing (e.g., including segments in at leastrouting tracks 1126A,1126B, 1126E, and 1126F) can cancel or reduce thecross-talk modulation (e.g., the cross-talk modulation becomes commonmode). Although FIG. 11D illustrates cross-talk mitigation for atwo-by-two array at 4:2 routing trace connected, it should be understoodthat this technique can be used for other routing traces to reducecross-talk for regions of a larger touch sensor panel.

As described herein, a differential drive and differential sensearchitecture can reduce noise in the touch and/or display systems of atouch screen that may arise due to the proximity of the touch system tothe display system. The use of differential drive and differential sensearchitecture, however, may result in a reduced signal-to-noise ratio forthe sensed touch signals due to parasitic non-idealities of theimplementation of the differential drive and differential sensearchitecture. In some examples, as described in more detail herein,staggering connections between the drive circuitry and column electrodesand/or between sense circuitry and row electrodes can reduce theparasitic effects and/or increase the signal-to-noise ratio fordifferential drive and differential sense architectures.

FIGS. 12A-12B illustrate an example touch node in a row-columnarchitecture using single-ended capacitance measurements or differentialcapacitance measurements according to examples of the disclosure. FIG.12A illustrates a row electrode 1202 and a column electrode 1204 of atouch sensor panel, with touch node 1200 corresponding to an adjacencybetween a portion of the row electrode 1202 and the column electrode1204. As shown in FIG. 12A, the column electrode 1204 can includemultiple coupled electrode segments 1204A-1204C, and the row electrode1202 can include multiple coupled electrode segments 1202A-1202C(coupling of the segments is not shown for simplicity).

A driving circuit 1206 can stimulate the row electrode 1202 and asensing circuit 1208 coupled to column electrode 1204 can measure acapacitance of touch node 1200. The capacitance measured by the sensingcircuit can primarily measure capacitive coupling between row electrodesegment 1202B and column electrode segment 1204B, illustrated bycapacitance CM (main capacitance) in FIG. 12A. However, in addition tomeasuring CM, the capacitance measurement can also include parasiticcapacitances from coupled between other row electrode segments andcolumn electrode segments of adjacent touch nodes. For example,parasitic couplings can include coupling between row electrode segments1202A and column electrode segments 1204B (C_(PR) or parasitic rowcoupling), coupling between row electrode segments 1202C and columnelectrode segments 1204B (C_(PR)), coupling between row electrodesegments 1202B and column electrode segments 1204A (C_(PC) or parasiticcolumn coupling), and coupling between row electrode segments 1202B andcolumn electrode segments 1204C (C_(PC)).

FIG. 12A illustrates a circuit diagram representing the drive circuit1206 for row electrode 1202 and the sensing circuit 1208 for columnelectrode 1204, with the capacitances measured for touch node 1200including the main capacitance, CM, and the combined parasiticcapacitance of two parasitic column couplings and two parasitic rowcouplings. Because the measurement is single-ended, these capacitancessum for a total measured capacitance of C_(M)+2C_(PC)+2C_(PR).

FIG. 12B illustrates a portion of a touch sensor panel including acolumn with two column electrodes including a first column electrode1214A (including two electrode segments illustrated in FIG. 12B) and asecond column electrode 1214B, and a row with two row electrodesincluding a first row electrode 1212A (including two electrode segmentsillustrated in FIG. 12B) and a second column electrode 1212B. Touch node1210 corresponding to an adjacency between column electrode 1214B andthe row electrode 1212B. A driving circuit 1216 can stimulate the rowelectrode 1212B with a drive signal and row electrode 1212B with acomplimentary drive signal (as indicated by the D+ and D− labels), and asensing circuit 1218 coupled to column electrode 1214B and columnelectrode 1214A can differentially measure (as indicated by S+ and S−labels) a capacitance of touch node 1210. The capacitance measured bythe sensing circuit can primarily measure capacitive coupling betweenrow electrode 1212B and column electrode 1214B, illustrated bycapacitance CM (main capacitance), and also measure the parasiticcapacitances. The parasitic capacitances can include coupling betweenrow electrode 1212A and column electrode segment 1214B (C_(PR), doubledfor the two adjacent segments shown in FIG. 12B), and coupling betweenrow electrode 1202B and column electrode 1214A (C_(PC), doubled for thetwo adjacent segments shown in FIG. 12B).

FIG. 12B illustrates a circuit diagram representing the drive circuit1216 for the row electrodes 1212A-1212B and the sensing circuit 1218 forcolumn electrodes 1214A-1214B, with the capacitances measured for touchnode 1210 including the main capacitance, CM, but attenuated by thecombined parasitic capacitances. Because of the differential drive anddifferent sense configuration, these parasitic capacitances are out ofphase and sum for a total measured capacitance of C_(M)−2C_(PC)−2C_(PR).The parasitic effects decrease the total measured signal, which reducesthe SNR. In some examples, the parasitic effects can decrease the totalmeasured signal by approximately 75%-80%, reducing the SNR for the touchsensor panel. Furthermore, the parasitic effects can reduce theeffectiveness of differential cancelation of noise described herein,which can also increase the noise (e.g., by approximately 3-5 times) andfurther degrading SNR.

In some examples, the SNR can be approved by changing the pattern ofstimulation applied to the touch sensor panel. The pattern can bechanged by the coupling between routing traces and the drive circuitry(e.g., optionally using switches or alternatively by changing the codesused generate drive signals in the driver circuitry). FIGS. 13A-13Billustrate portions of touch sensor panels and representations ofstimulation applied the touch sensor panels according to examples of thedisclosure. Touch sensor panel 1300 can correspond to touch sensor panel700. Touch sensor panel 1300 can include row electrodes 1302A-1302F(e.g., corresponding to row electrodes 702A-702F) and column electrodes1304A-1304F (e.g., corresponding to row electrodes 704A-704F). Touchsensor panel can be viewed as including a two dimensional array (threerows and three columns) of effective touch nodes, with each of the touchnodes including one row electrode segment and one column electrodesegment. The row electrodes can be coupled to sensing circuitry and thecolumn electrodes can be coupled to driver circuitry (e.g., adriver/transmitter). For example, FIG. 13A illustrates a differentialdriver circuit 1305A (or two single-output driver circuits) coupled tocolumn electrodes 1304A and 1304B, differential driver circuit 1305Bcoupled to column electrodes 1304C and 1304D, and differential drivercircuit 1305C coupled to column electrodes 1304E and 1304F (e.g.,generating coded, complimentary drive signals). Differential amplifiers1308A-1308C (or multiple single-ended amplifiers) can be coupled to arespective pair of row electrodes 1302A-1302F.

Touch sensor panel 1300 can be viewed as an expansion of the view of aportion of a touch sensor panel presented in FIG. 12B (although therow/column conventions for driving and sensing are different betweenFIGS. 12B and 13A). For example, touch node 1210 can correspond to thetouch node in the center of touch sensor panel 1300 corresponding tocolumn electrode 1304D and row electrode 1302D. The polarity of thedrive signal applied to adjacent column electrode 1304C is complimentaryin a similar manner as shown by the complimentary phase of adjacent rowelectrode 1212A, and likewise the polarity for the differentialamplifier terminal coupled to adjacent row electrode 1302C is oppositethe polarity of row electrode 1302D as shown by the opposite polarity ofadjacent column electrode 1214A.

FIG. 13A also illustrates a representation 1310 of the stimulationapplied to a touch sensor panel. Representation 1310 shows stimulationof a 4×4 array of touch nodes though the portion of touch sensor panel1300 shown in FIG. 13A only shows a 3×3 array. Representation 1310 showsthat a set of complimentary drive signals is used within each column(e.g., with the drive signals labeled TX0, TX1, etc. using indexingcorresponding to the driver circuits with labels D0, D1, etc.). Forexample, the leftmost column uses opposite phases of TX0 (alternating +and −), and each column to the right uses opposite phases of TX1, TX2,and TX3, respectively (where TX0, TX1, TX2 and TX3 can be orthogonaldrive signals). In a similar manner, each row of row electrodes couplesto the differential input of one corresponding differential amplifier.As described with respect to FIG. 12B, such a configuration can besusceptible to a reduction in SNR due to parasitic capacitances.

FIG. 13B illustrates touch sensor panel 1320 corresponding to touchsensor panel 1300, but having different coupling between the drivercircuitry and the column electrodes. For example, as shown in FIG. 13B,the complimentary drive signals can be applied in different columns suchthat the complimentary drive signals are diagonally adjacent(staggered). For example, as shown in representation 1330 of thestimulation applied to a touch sensor panel, each drive signal can haveits compliment applied to the touch node (using the column electrode)that is offset by one row and one column. For example, TX0+ is appliedto the touch node at column 1, row 1 and its compliment is applied tothe touch node at column 2, row 2. Similar relationships for thecomplimentary touch signals can be applied across the touch sensorpanel. Staggering the complimentary drive signals can reduce the size ofparasitic capacitances (e.g., C_(PC) shown in FIG. 12B) because thediagonal distance between the electrodes is greater than non-diagonallyadjacent electrodes, and thereby increase the signal (boosting SNR). Insome examples, the boost in signal can be between 80%-100% (or more)compared with the non-staggered stimulation pattern of FIG. 13A. Itshould be understood that staggering increases the differentialcancelation pitch (e.g., the distance between the complimentarysignals), which increases the area over which the differential signalscancel. As a result, increasing the differential cancelation pitch canresult in less cancelation of coexistence noise (e.g., an increase intouch-to-display noise). However, the reduction in cancelation ofcoexistence noise may be outweighed by the improved signal level toimprove SNR. Although staggering is shown for diagonally adjacent touchnodes in pairs of columns that other staggering patterns are possible,with a tradeoff between the level of suppression of coexistence noise(which improves with a smaller differential cancelation pitch) with thesignal level (which improves by increasing the distance between thedrive electrodes with opposite phase). It should also be understood thatbecause display-to-touch noise is primarily mitigated by differentialsensing, that staggering the stimulation pattern should not impact (orhave minimal impact on) the level of display-to-touch noise.

As shown in FIG. 13B, staggering can be implemented by changing therouting between the column electrodes and the driving circuitry. Forexample, the routing traces output by driver circuit 1306A can includeone output to column electrode 1304A and the complimentary output tocolumn electrode 1304D (rather than to 1304B as in FIG. 13A). Likewise,the routing traces output by driver circuit 1306B can include one outputto column electrode 1304C and the complimentary output to columnelectrode 1304B (rather than to 1304D as in FIG. 13A). In some examples,the staggering can be implemented using the driver circuitry withoutchanging the routing between the driver circuitry and the electrodes ofthe touch sensor panel. For example, switching circuitry can beimplemented between the output of the driver circuitry and the routingtraces to achieve the staggered pattern of drive signals. Alternatively,the driver circuitry can be configured to generate the staggered patternusing different control signals (e.g., output TX0− from the output ofdriver circuit 1305B coupled to column electrode 1304D in FIG. 13A andoutput TX1− from the output of driver circuit 1305A coupled to columnelectrode 1304B. Implementing the staggering pattern without changingthe routing can provide improved flexibility for implementingdifferential and non-differential scans. For example, although the touchsensing may be implemented using a differential configuration, in someexamples, stylus sensing can be implemented without using differentdriving or different sensing. For example, the plurality of firstelectrodes and the plurality of second electrodes can be configured asreceiver electrodes in an active stylus sensing operation. The first rowelectrode and a second row electrode for each row of the two-axis arrayof touch nodes can be coupled together and to an input of a sensingcircuit. Thus, implementing the staggering pattern without changing therouting allows for implementation of either differential or single-endedscanning modes.

In some examples, the differential driving and sensing can operate indifferent modes for touch sensing based on noise conditions. Forexample, the touch system may perform a touch sensing operation usingstaggering described herein under relatively more noisy conditions(e.g., above a threshold amount of noise, while a charger is plugged in,etc.) so that the sensed signal can be boosted (but with lesscancelation of coexistence noise), but the touch system may perform atouch sensing operation without staggering under relatively less noisyconditions (e.g., less than the threshold amount of noise, while notplugged into the charger, etc.) so that the improved cancelation canoccur, but the signal level may be relatively small (e.g., attenuatedcompared with staggering).

Although staggering is described primarily in the context of thestimulation applied to the column electrodes of FIG. 13B, it isunderstood that a similar principle can be additional or alternativelyapplied to staggering the connections between the row electrodes andsensing circuitry. For example, rather than sensing both row electrodesin a row differentially using one differential amplifier, in someexamples, one row electrode can be coupled to a first input of a firstdifferential amplifier and a second row electrode can be coupled to afirst input of a second differential amplifier. It is understood that ifstaggering is implemented for both the stimulation and sensing sides ofthe touch sensor panel that care should be taken so that staggeringapplied to the stimulation side and the staggering applied to thesensing side do not interfere with the ability to measure thedifferential touch signal.

As described herein, in some examples, routing for including rowelectrodes and column electrodes of a touch sensor panel can beimplemented at least partially in the active area. Active area routingcan allow for a device with a reduced border area (e.g., around theactive area). FIGS. 14A-14B illustrate a two-layer configuration (e.g.,corresponding to touch sensor panel 700) including touch electrodes androuting traces in a first layer and bridges in a second layer accordingto examples of the disclosure. Specifically, FIG. 14A illustrates afirst layer 1400A (also referred to herein a “metal 2” or “TM2”) of thetwo-layer configuration and FIG. 14B illustrates a second layer 1400B(also referred to herein a “metal 1” or “TM1”) of the two-layerconfiguration. The first layer 1400A and the second layer 1400B can bothbe metal mesh layers corresponding to metal layers 506 and 516. In someexamples, the first layer including touch electrodes can be positionedrelatively closer to the cover glass than the second layer. To show theoverlapping contents of the layers, FIGS. 14A-14B each illustrate thetouch electrodes, routing traces and bridges, but touch electrodes androuting traces in layer 1400A are emphasized and the bridges in layer1400B are deemphasized in FIG. 14A, whereas bridges in layer 1400B areemphasized and touch electrodes and routing traces in layer 1400A aredeemphasized in FIG. 14B. The emphasis is provided with darker/thickerlines compared with the lighter/thinner lines for deemphasized contents.

FIG. 14A illustrates row electrodes 1402A-1402F and column electrodes1404A-1404F (e.g., corresponding to row electrodes 702A-702F and columnelectrodes 704A-704F). Additionally, FIG. 14A illustrates row routingtraces 1403A-1403F and column routing traces 1405A-1405F (e.g.,corresponding to row routing traces 703A-703F and column routing traces705A-705F). FIG. 14B illustrates bridges 1410, which can be connected tothe first layer using a pair of vias at opposite ends of the bridge(e.g., horizontal ends). Unlike in FIG. 7A, which illustrates therouting traces in a different layer than the touch electrodes, in FIGS.14A-14B the routing traces are implemented in the same layer. As aresult, the routing traces that may be used to interconnect segments oftouch electrodes together (and to drive/sense circuitry) may also causefurther segmentation of the metal mesh of the touch electrodes. In someexamples, these segments of the touch electrodes can be electricallyinterconnected using bridges. For example, the column electrodes1404A-1404F can include multiple conductive segments interconnected byrouting and/or bridges. Likewise, row electrodes 1402A-1402F can includemultiple conductive segments connected together and to sensing circuitryby routing and/or bridges.

As an illustrative example, column electrode 1404A can includeconductive segments 1404A_1-1404A_5 (rather than two segments shown inFIG. 7 due to routing traces 1403C and 1405B) that are connectedtogether and to driving circuitry by routing trace 1405A (includingrouting trace segments 1405A_1-1405A_3) and bridges 1410 (includingbridges 1410A_1-1410A_3 that bridge the conductive segments over routingtraces 1403C and 1405B). As another illustrative example, row electrode1402A can include conductive segments 1402A_1-1402A_13 (rather than twosegments 702A′ and 702A″ connected by routing 702A′″ as shown in FIG. 7due to routing traces including 1405A-1405F, additional row routingtrace lines) that are connected together and to sensing circuitry byrouting 1403A and bridges 1410 (including bridges 1410B_1-1410B_10 thatbridge the conductive segments over routing traces including1405A-1405F).

It is understood that FIG. 14A-14B show an exemplary representation ofelectrodes, routing and bridges, but that other arrangements of theelectrodes, routing and bridges can be implemented. It is alsounderstood that for simplicity of illustration some bridges betweenconductive segments may not be shown (e.g., conductive segment 1402A_1,conductive 1402A_3 and/or conductive segment 1402A_11 may extend beyondand be connected at the bottom edge(s) of conductive segment 1404A_1,including by one or more bridges over routing traces, such as overrouting trace 1405A_2). Although FIGS. 14A-14B illustrate two verticalrouting traces for complimentary drive signals per column of columnelectrodes and two vertical routing traces per row of row electrodes(e.g., two vertical routing traces per pair of row electrode), it shouldbe understood that different numbers of vertical routing traces for rowsand/or columns is possible. It should be understood that although touchsensor panel of FIGS. 14A-14B includes a 3×3 array of nine dominantcapacitance values (e.g., corresponding to nine effective touch nodes),that the touch sensor panel can be scaled up or down to include fewer ormore touch nodes.

FIGS. 14A and 14C illustrate a two-layer configuration (e.g.,corresponding to touch sensor panel 700) including touch electrodes androuting traces in a first layer and bridges and stacked routing tracesin a second layer according to examples of the disclosure. Stacking therouting traces can reduce the resistance of the routing traces andincrease the bandwidth of the touch sensor panel compared with thetwo-layer configuration of FIGS. 14A-14B without the stacked routingtraces. Specifically, FIG. 14A illustrates a first layer 1400A (alsoreferred to herein a “metal 2” or “TM2”) of the two-layer configurationand FIG. 14B illustrates a second layer 1400C (also referred to herein a“metal 1” or “TM1”) of the two-layer configuration. The first layer1400A and the second layer 1400C can both be metal mesh layerscorresponding to metal layers 506 and 516. In some examples, the firstlayer including touch electrodes can be positioned relatively closer tothe cover glass than the second layer. To show the overlapping contentsof the layers, FIGS. 14A and 14C each illustrate the touch electrodes,routing traces and bridges, but touch electrodes and routing traces inlayer 1400A are emphasized and the bridges in layer 1400C aredeemphasized in FIG. 14A, whereas bridges and routing in layer 1400C areemphasized and touch electrodes and routing traces in layer 1400A aredeemphasized in FIG. 14C. The emphasis is provided with darker/thickerlines compared with the lighter/thinner lines for deemphasized contents.

As described herein, FIG. 14A illustrates row electrodes 1402A-1402F,column electrodes 1404A-1404F, row routing traces 1403A-1403F and columnrouting traces 1405A-1405F. FIG. 14C illustrates bridges 1410, rowrouting trace 1413A-1413F and column routing traces 1415A-14145F.Bridges 1410 can be connected to the first layer using a pair of vias atopposite ends of the bridge (e.g., horizontal ends) to connect segmentsthat are otherwise electrically disconnected due to a routing trace.Unlike in FIG. 14B, which illustrates bridges without routing traces inthe second layer, in FIG. 14C, the second layer can also includeadditional routing traces corresponding to the routing traces in thefirst layer (stacked routing traces). The routing traces in layers 1400Aand 1400C can be coupled together outside the active area or using viaswithin the active area.

For example, in addition to coupling the segments of column electrode1404A together and to driving circuitry using routing trace 1405A(including routing trace segments 1405A_1-1405A_3) in layer 1400A,additional routing trace segments 1415A_1-1415A_5 in the second layer1400C can be used to reduce the effective resistance of the routingtrace (e.g., by approximately half). For example, routing trace segment1415A_1 can run parallel to routing trace segment 1405A_1 and routingtrace segments 1415A_3 and 1415A_4 can run parallel to routing tracesegment 1405A_2, and so on. Additionally, routing trace segments 1415A_2and 1415A_5 can run parallel to routing trace segments 1404A_5 and1404A_1, respectively, as well.

In a similar manner, stacked routing can be used for row routing traces.For example, in addition to coupling the segments of row electrode 1402Atogether using bridges 1410 (in layer 1400C) and to sensing circuitryusing routing trace 1403A in layer 1400A, additional routing tracessegments 1413A_1-1413A_5 in the second layer 1400C can be used to reducethe effective resistance of the routing trace (e.g., by approximatelyhalf). For example, routing trace segments 1415A_1-1415A_5 can runparallel to row routing trace 1403. The routing trace segments in layer1400C can be interrupted by the bridges in layer 1400C.

It is understood that FIGS. 14A and 14C show an exemplary representationof electrodes, routing and bridges, but that other arrangements of theelectrodes, routing and bridges can be implemented. It is alsounderstood that for simplicity of illustration some bridges betweenconductive segments may not be shown (e.g., conductive segment 1402A_1,conductive 1402A_3 and/or conductive segment 1402A_11 may extend beyondand be connected at the bottom edge(s) of conductive segment 1404A_1,including by one or more bridges over routing traces, such as overrouting trace 1405A_2). Although FIGS. 14A and 14C illustrate twovertical routing traces for complimentary drive signals per column ofcolumn electrodes and two vertical routing traces per row of rowelectrodes (e.g., two vertical routing traces per pair of rowelectrode), it should be understood that different numbers of verticalrouting traces for rows and/or columns is possible. It should beunderstood that although touch sensor panel of FIGS. 14A and 14Cincludes a 3×3 array of nine dominant capacitance values (e.g.,corresponding to nine effective touch nodes), that the touch sensorpanel can be scaled up or down to include fewer or more touch nodes.

FIGS. 15A-15B illustrate partial views 1500 and 1550 of a region 1450 ofthe two-layer configuration of FIGS. 14A-14C including two touchelectrode segments 1552A-1552B and a routing trace 1158 in the firstlayer (e.g., metal 2 layer) and a bridge 1554 and optionally stackedrouting trace segments 1556A-1556B in the second layer (metal 1 layer)according to examples of the disclosure. Partial view 1500 correspondsto the two-layer configuration of FIGS. 14A and 14B, whereas partialview 1550 corresponds to the two-layer configuration of FIGS. 14A and14C. Although not shown the first and second layers can be separated byan insulating layer (e.g., a dielectric layer). The electrodes, routing,and bridges in FIGS. 15A-15B are shown as a mesh representative of ametal mesh implementation of the electrodes. As described herein, oneend of bridge 1554 can be coupled to touch electrode segments 1552A(e.g., using a via through an intermediate dielectric layer separatingthe first and second layers) and a second end of bridge 1554 can becoupled to touch electrode segment 1552B (e.g., using a via through anintermediate dielectric layer separating the first and second layers).Stacked routing trace segments 1556A-1556B in partial view 1550 (but notshown in partial view 1500 or in corresponding FIG. 14B) can each becoupled to routing trace 1558 (e.g., using vias through the intermediatedielectric layer).

FIG. 16 illustrates a partial view 1650 of the two-layer configurationincluding stacked touch electrode segments 1652A-1652D in the firstlayer and the second layer (including a bridging portion 1654), arouting trace 1658 in the first layer and stacked routing trace segments1656A-1656B in the second layer according to examples of the disclosure.Stacking the routing traces and stacking the touch electrodes canincrease the bandwidth of the touch sensor panel compared with thetwo-layer configuration of FIGS. 14A-14B without the stacked routingtraces and without stacked electrodes and compared with the two-layerconfiguration of FIGS. 14A and 15A without the stacked touch electrodes.For example, in addition to reducing the resistance of the routingtraces, the stacked touch electrodes can increase the capacitive signalcoupling. FIG. 16 includes a partial view of for ease of illustration,but it is understood that stacked touch electrodes and stacked routingtraces can be implemented throughout a touch sensor panel as describedherein. Additionally, the stacked touch electrodes of FIG. 16 provideflexibility for placement of the via between touch electrode segments ofthe two layers in comparison to the configurations of FIGS. 14A-15B. Forexample, in FIG. 14B and FIG. 15B, the opposite ends of each bridge canbe connected using two vias (e.g., one via per end) to interconnect thetwo segments using the bridge. However, as shown in FIG. 16 , thestacked touch electrode including touch electrode segments 1652C-1652Dand bridging portion 1654 are interconnected in the second layer, andcan be interconnected with the touch electrode segments 1652A-1652B atany overlapping region between the touch electrode segments between thetwo layers.

Stacking routing and/or touch electrodes as described herein can resultin reduced optical performance (e.g., visibility of the metal mesh) fora device. In particular, misalignment between metal mesh between thefirst layer and the second layer can increase the visibility of metalmesh to a user. FIGS. 17A-17D illustrate cross-sectional views 1700,1710, 1720 and 1730 of a portion of example two-layer configurationsaccording to examples of the disclosure. FIGS. 17A-17B illustratecross-sectional views of a portion of the two-layer configuration withmetal mesh 1702/1702′ in the first layer disposed on an inter-layerdielectric (ILD) 1704, which can be disposed on metal mesh 1706 in thesecond layer. The metal mesh can correspond to routing trace segments inthe first and second layers corresponding to stacked routing. The metalmesh in the first layer the in the second layer can have equal widths(e.g., the trapezoid representing the metal mesh trace can have the samebase width). In FIG. 17A, the metal mesh 1702 in the first layer and themetal mesh 1706 in the second layer can be aligned such that metal mesh1706 in the second layer may not be visible to a user looking down atthe top of the first layer. However, as shown in FIG. 17B, when themetal mesh 1702′ in the first layer is not aligned with the metal mesh1706 in the second layer (e.g., due to due to manufacturinglimitations), metal mesh 1706 in the second layer can be visible to auser looking down at the top of the first layer.

In some examples, increasing the width of metal mesh in the first layerand/or shrinking the width of the metal mesh in the second layer canimprove the optical performance by ensuring that the metal mesh in thefirst layer overlaps the metal mesh in the second layer. FIGS. 17C-17Dillustrate cross-sectional views of to portion of the two-layerconfiguration with metal mesh 1712/1712′ in the first layer disposed onan inter-layer dielectric (ILD) 1704, which can be disposed on metalmesh 1706 in the second layer. The metal mesh can correspond to routingtrace segments in the first and second layers corresponding to stackedrouting. The metal mesh in the first layer the in the second layer canhave unequal widths. In particular, the metal mesh 1712/1712′ in thefirst layer (“TM2”) can be wider than the metal mesh in the second layer(“TM1”) to improve optical performance of the touch sensor panel. Asshown in FIGS. 17C-17D, whether the metal mesh 1712 in the first layeraligns (e.g., is centered) with the metal mesh 1706 in the second layeror whether the metal mesh 1712′ is offset (off-center) from that metalmesh 1706 in the second layer, metal mesh 1706 may not be visible to auser looking down at the top of the first layer, thereby reducing thevisibility of the metal mesh overall.

In some examples, the visibility improvement can be achieved byincreasing the width of the metal mesh 1712/1712′ compared with thewidth of metal mesh 1702/1702′. In some examples, the visibilityimprovement can be achieved by decreasing the width of the metal mesh1706 shown in FIGS. 17C-17D compared with the width of metal mesh 1706shown in FIGS. 17A-17B. In some examples, the visibility improvement canbe achieved by increasing the width of the metal mesh 1712/1712′compared with the width of metal mesh 1702/1702′ and decreasing thewidth of the metal mesh 1706 shown in FIGS. 17C-17D compared with thewidth of metal mesh 1706 shown in FIGS. 17A-17B. For example, metal mesh1702 and metal mesh 1706 can be 4 microns wide each in FIG. 17A, butmetal mesh 1712 and metal mesh 1706 can be 5 microns and 3 microns wide,respectively.

In some examples, optical performance of a touch sensor panel can beimproved by implementing a touch electrode partially in two layersrather than fully stacking the touch electrodes (e.g., as shown in FIG.16 ). FIG. 18 illustrates a portion of a two-layer configurationincluding a configuration 1800 of a touch electrode implementedpartially in a first layer and partially in a second layer according toexamples of the disclosure. For example, metal mesh 1802A can beimplemented in a first layer and metal mesh 1802B can be implemented ina second layer. Referring back to FIG. 16 , touch electrode segments1652A and 1652C overlap and touch electrode segments 1652B and 1652Doverlap. As a result, in order to reduce optical artifacts, thealignment of the metal mesh traces (e.g., described in FIG. 17A) must bemaximized across relatively large area of the touch electrode. Forexample, FIG. 16 shows the horizontal and/or vertical portions of themetal mesh in parallel between the two layers. In contrast, inconfiguration 1800 of FIG. 18 , the metal mesh 1802A can be implementedin a first layer and the metal mesh 1802B can be implemented in a secondlayer such that the overlap between the two layers is reduced.Furthermore, as shown in FIG. 18 , when the metal mesh 1802A in thefirst layer and the metal mesh 1802B in the second layer overlap, theoverlapping point is a non-parallel intersection (e.g., orthogonalcrossing). For example, crossing point 1804 can represent a square orrectangular overlapping area at which the metal mesh 1802A and metalmesh 1802B overlap. This same square or rectangular overlapping area canappear at each crossing point shown in FIG. 18 . As a result, theappearance of the metal mesh between the first and second layers canhave relatively uniform appearance across the touch sensor panel (e.g.,uniform area at crossing points and uniform width outside of thecrossing points).

As with FIG. 16 , the configuration 1800 of FIG. 18 also providesflexibility in terms of placement of vias (e.g., not limited to bridgesas in the configurations of FIGS. 14A-15B). However, it should beunderstood that the bandwidth improvement from the configuration of FIG.18 is relatively less than the bandwidth improvement from theconfiguration of FIG. 16 (e.g., because there is less metal mesh used toimplement the touch electrode across the two layers), whereas theoptical performance of the configuration of FIG. 18 may be greater thanthe optical performance of the configuration of FIG. 16 .

As described herein (e.g., with respect to FIG. 11A-11D), in someexamples, the routing traces for a row to a (differential) senseamplifier can impact cross-talk between adjacent rows within a column.In some examples, the cross-talk can be mitigated using differentialrouting traces as described with reference to FIG. 11D, for example,when performing differential measurements. However, some touch sensorpanel operations may not include differential measurements. For example,a self-capacitance scan—in which the touch electrodes can be stimulatedwith the same phase drive signal simultaneously—or a stylus scan may notbe performed differentially. In some examples, the cross-talk can bereduced by burying the routing trace (e.g., rather than stacking therouting trace as described with reference to FIG. 15A or FIG. 16 ).

FIG. 19A illustrates a partial view 1900 of a two-layer configurationincluding stacked touch electrode segments 1952A-1952D in the firstlayer and the second layer and stacked routing traces 1956-1958 in thefirst layer and the second layer according to examples of thedisclosure. FIG. 19A can correspond to FIG. 16 at a region without abridging portion 1654. FIG. 19A also illustrates a correspondingcross-sectional view of a portion of the two-layer configuration withmetal mesh 1902 in the first layer disposed on an inter-layer dielectric(ILD) 1904, which can be disposed on metal mesh 1906 in the secondlayer. FIG. 19B illustrates a partial view 1910 of a two-layerconfiguration including stacked touch electrode segments 1962A-1962C inthe first layer and the second layer and buried routing trace 1966 inthe second layer according to examples of the disclosure. FIG. 19A alsoillustrates a corresponding cross-sectional view of a portion of thetwo-layer configuration with metal mesh 1902 in the first layer disposedon an inter-layer dielectric (ILD) 1904, which can be disposed on metalmesh 1906 in the second layer. Unlike FIG. 19A, in FIG. 19B, the buriedrouting trace 1966 can be shielded at least partially from cross-talkdue to an object (e.g., a finger or stylus) in proximity to the touchsensor panel. In some examples, the cross-coupling can be reduced fromapproximately 10% of the full-scale touch signal to approximately 2% ofthe full-scale touch signal.

Although burying the routing trace can reduce cross-talk, the increasein metal mesh can also increase parallel plate capacitance between thefirst layer and the second layer, which can decrease the bandwidth ofthe touch sensor panel. In some examples, the increase in parallel platecapacitance can be mitigated by changing properties of the ILD. FIG. 19Cillustrates a partial view 1920 of a two-layer configuration includingstacked touch electrode segments 1972A-1972C in the first layer and thesecond layer and buried routing trace 1976 in the second layer accordingto examples of the disclosure. FIG. 19C also illustrates a correspondingcross-sectional view of a portion of the two-layer configuration withmetal mesh 1902 in the first layer disposed on an inter-layer dielectric(ILD) 1904′, which can be disposed on metal mesh 1906 in the secondlayer. The metal mesh touch electrodes and routing traces of FIG. 19Ccan be the same or similar to the touch electrodes and routing traces ofFIG. 19B. However, the ILD can be modified to have a thickness T2 inFIG. 19C greater than the thickness T1 in FIG. 19B (and as shown thefirst and second layers in views 1920 are separated from one anothermore than the first and second layers in view 1910). In some examples,the thickness increase can be between 25%-500%. In some examples, thethickness increase can be between 100%-250%. In some examples, thethickness increase can be between 150%-200%. It should be understoodthat the above ranges are examples, and that thickness can be increasedto achieve the desired bandwidth for the touch sensor panel.

Additionally or alternatively, the ILD can be modified to have adifferent dielectric constant in FIG. 19C less than the dielectricconstant of the ILD in FIG. 19B. In some examples, the dielectricconstant of the ILD in FIG. 19C can be between 25%-75% of the dielectricconstant of the ILD in FIG. 19B. In some examples, the dielectricconstant of the ILD in FIG. 19C can be between 25%-50% of the dielectricconstant of the ILD in FIG. 19B. It should be understood that the aboveranges are examples, and that dielectric can be decreased to achieve thedesired bandwidth for the touch sensor panel. In some examples, thedielectric constant can be lowered by using an organic material such asa photo-patternable ultraviolet-cured acrylic or other suitablematerial.

Because parallel plate capacitance is proportional to the dielectricconstant and inversely proportional to the separation distance betweenthe plates, increasing the ILD thickness or decreasing the dielectricconstant of the ILD can reduce the parallel plate capacitance andimprove the touch sensor panel bandwidth.

As described herein, the SNR of the touch sensor panel using metal meshtouch electrodes can be relatively low compared with a touch sensorpanel using a transparent conductor such as indium tin oxide.Conceptually, the source of the signal loss can be that the non-solidstructure of metal mesh (e.g., gaps) permit some exposure of deviceground (e.g., display cathodes) such that only a portion of the signalis coupled to the metal mesh. In some examples, the signal loss can bebetween 30-70% depending on the size of the object in proximity to thetouch sensor panel. In some examples, to boost SNR (e.g., boost touchsignal), the metal mesh in the first layer can be flooded or otherwisefilled with a transparent conductive material (e.g., ITO).

FIG. 20A illustrates a partial view 2000 of a two-layer configurationincluding stacked touch electrode segments 2052A-2052D in the firstlayer and the second layer and stacked routing traces 2056-2058 in thefirst layer and the second layer according to examples of thedisclosure. FIGS. 20B-20C illustrate examples of correspondingcross-sectional views of a portion of the two-layer configurationincluding an ITO flood according to examples of the disclosure. As shownin FIG. 20A (and unlike FIG. 19A), the metal mesh of touch electrodesegments 2052A-2052B and routing trace 2058 in the first layer can befilled (e.g., flooded) partially or fully with a transparent conductivematerial, such as ITO or any other suitable transparent orsemi-transparent conductive material. The conductive material can fillthe gaps in the metal mesh and boost the signal received at the touchelectrodes (e.g., the signal is received by the ITO rather than passingthrough to ground electrodes within the device). In some examples, themetal mesh of the touch electrodes can have low resistancecharacteristics relative to the transparent conductor, so that the metalmesh can handle the conduction required for touch sensing. As a result,the requirements of the sheet resistance of the transparent conductorcan be reduced. In some examples, a relaxed sheet resistance for thetransparent conductor can allow for low-temperature depositiontechniques to be used (e.g., low-temperature ITO deposition).

In some examples, as shown in FIG. 20B, the transparent conductor can bedeposited on the metal mesh and be deposited directly on the metal meshlayer. For example, FIG. 20B illustrates a cross-sectional view of aportion of the two-layer configuration with metal mesh 2002 in the firstmetal mesh layer disposed on an inter-layer dielectric (ILD) 2004, whichcan be disposed on metal mesh 2006 in the second metal mesh layer. ITO2001 (or another suitable transparent conductor) can be deposited on themetal mesh 2002. As described herein, connections between the first andsecond layers of metal mesh can be achieved using vias in the ILD. Insome examples, as shown in FIG. 20C, the transparent conductor can beseparated from the metal mesh layer by another ILD. For example, FIG.20C illustrates a cross-sectional view of a portion of the two-layerconfiguration with metal mesh 2002 in the first metal mesh layerdisposed on a first inter-layer dielectric (ILD) 2004B, which can bedisposed on metal mesh 2006 in the second metal mesh layer. A second ILD2004A can be deposited on the metal mesh 2002, and the ITO 2001 (oranother suitable transparent conductor) can be deposited on second ILD2004A. As described herein, connections between the first and secondlayers of metal mesh can be achieved using vias in the ILD.Additionally, the connections between the ITO 2001 and the metal mesh2002 can be achieved using vias through the second ILD 2004A.

Additionally or alternatively, in some examples, rather than burying therouting trace as described with reference to FIG. 19B-19C, cross-talkcan be reduced by using a fill of a conductive material for selectedportions of the metal mesh (e.g., a selective ITO fill). FIG. 21illustrates a partial view 2100 of a two-layer configuration includingstacked touch electrode segments 2152A-2152D in the first layer and thesecond layer and stacked routing traces 2156-2158 in the first layer andthe second layer according to examples of the disclosure. As shown inFIG. 21 (and unlike FIG. 20A), the metal mesh of touch electrodesegments 2152A-2152B in the first layer can be filled (e.g., flooded)partially or fully with a transparent conductive material, such as ITOor any other suitable transparent or semi-transparent conductivematerial, without filling routing trace 2158 with the conductivematerial (e.g., using a mask to prevent filling). In some examples, therouting trace 2058 can also be filled, but the fill of conductivematerial can be etched away. The conductive material can fill the gapsin the metal mesh touch electrodes and boost the signal received at thetouch electrodes (e.g., the signal is received by the ITO rather thanpassing through to ground electrodes within the device). However, thecross-talk coupling through the routing trace 2158 can be un-boosted(e.g., reduced to 4-6% of the full scale touch signal at touchelectrodes 2152A-2152B) without the fill for the routing trace 2158. Asa result, the cross-talk can be reduced using selective ITO flooding,without burying the routing trace as described with reference to FIG.19B-19C.

It should be understood that although described separately, the variousfeatures described herein can be used in combination. For example,burying of the routing trace described with reference to FIG. 19B can becombined with an improved ILD characteristic described with reference toFIG. 19C and/or with an improved signal characteristic of ITO floodingdescribed with reference to FIGS. 20A-20C. As another example, therouting techniques described with reference to FIGS. 14A-21 can beapplied to the touch sensor panels described with reference to FIGS.7A-13B.

As described herein, in some examples, noise from the display can coupleto touch electrodes due at least in part to the proximity of the displayto the touch electrodes of a touch sensor panel. In some examples, ashield layer or display-noise sensor can be disposed on a printed layer(e.g., an encapsulation layer) to reduce the noise from the display.FIG. 22 illustrates an example touch screen stack-up 2200 including anencapsulation layer 2208 and optional dielectric layer 2214 forisolation according to examples of the disclosure. In some examples,various layers of stack-up 2200 can be formed using a sharedmanufacturing process. In such examples, components are manufactured anddisposed onto their respective locations within stack-up 2200 in aserial fashion (e.g., without relying on discrete components that aremanufactured at a prior time, and then transferred to a location withinstack-up 2200). In some examples, components that are both manufacturedand disposed onto their respective locations within stack-up 2200, andnot manufactured separately as discrete, or semi-discrete components,can be referred to as on-chip fabricated/manufactured components, orcomponents fabricated using on-chip technologies for manufacturing. Asdiscussed below, stack-up 2200 includes multiple such components thatare fabricated using on-chip technologies for manufacturing, which offerseveral advantages over alternative “discrete” components that requirebeing transferred to stack-up 2200.

Stack-up 2200 can be built or fabricated upon substrate 2202, in someexamples. Substrate 2202 can be a printed circuit board substrate, asilicon substrate, or any other suitable base substrate material(s) forstack-up 2200. Display components 2204 (e.g., corresponding to displaycomponents 508) can be formed over substrate 2202, in some examples, andcan include a plurality of display elements arranged in an array (e.g.,in rows and columns). Each display element can comprise a display pixel,in some examples. A display pixel can correspond to light-emittingcomponents capable of generating colored light, in some examples.Examples of display pixels can include a backlit Liquid-Crystal Display(LCD), or a Light-Emitting Diode (LED) display, including Organic LED(OLED), Active-Matrix Organic LED (AMOLED), and Passive-Matrix OrganicLED (PMOLED) displays. In some examples, a display pixel can include anumber of sub-pixels (e.g., one, two, three, or more sub-pixels). As anexample, a display pixel can include a red sub-pixel, a green sub-pixel,and a blue sub-pixel, where the various sub-pixels have respectivedimensions relative to each other, and relative to the dimensions of theentire display pixel. In some examples, red, green, and blue sub-pixelscan have approximately, or substantially similar dimensions to oneanother (e.g., the sub-pixels are all within a 5% range of a targetdimension or area for the sub-pixels). In other examples, a bluesub-pixel can occupy approximately 50% of the area of a display pixel,with red and green sub-pixels occupying the remaining 50% of the area(e.g., each occupying 25% of the display pixel area). In some examples,display components 2204 are formed over the entirety of substrate 2202.In other examples, display components 2204 are formed over portions ofsubstrate 2202 (e.g., some portions of substrate 2202 do not havedisplay components 2204 formed over them).

Passivation layer 2206 can be formed over display components 2204, insome examples. In some such examples, passivation layer 2206 can be indirect contact with display components 2204. Similar to layers 507 and517 described in connection with FIG. 5 , passivation layer 2206 canplanarize the surface of display components 2204 and can provideelectrical isolation to display components 2204 (e.g., isolation fromcomponents in other layers formed above passivation layer 2206). In someexamples, passivation layer 2206 is formed after all of the displaysub-pixels and pixels (e.g., of display components 2204) have beenfabricated or formed over substrate 2202. In some examples, passivationlayer 2206 is formed over the entirety of display components 2204. Insome examples, additional passivation layers similar to passivationlayer 2206 can be formed over any of the layers of stack-up 2200 whosemanufacture can result in an uneven surface (e.g., a surface that isdifficult to form additional layers over). In some examples, anadditional passivation layer similar to passivation layer 2206 can beprovided over first encapsulation layer 2208 such that it directlycontacts the first encapsulation layer, and/or provided over secondencapsulation layer 2212 such that it directly contacts the secondencapsulation layer. In some such examples, forming a passivation layerover the first encapsulation layer and/or the second encapsulation layercan improve the accuracy and manufacturability of components/layers instack-up 2200 formed above those layers.

A first encapsulation layer 2208 can be formed over passivation layer2206, in some examples. In some such examples, first encapsulation layer2208 can be in direct contact with passivation layer 2206. Firstencapsulation layer 2208 can be referred to as a “printed layer,” whenit is deposited over/onto passivation layer 2206 using a printing ordeposition technique, in some examples. First encapsulation layer 2208can be deposited onto passivation layer 2206 using an ink-jet printingtechnique, in some examples. Ink-jet printing techniques can causelayers to be selectively deposited (e.g., deposited over a portion of anunderlying layer), or globally/blanket deposited (e.g., deposited overan entirety of the underlying layer), in some examples. In someexamples, first encapsulation layer 2208 can be ink-jet printedselectively over regions of passivation layer 2206 under which displaycomponents 2204 are formed. In other examples, first encapsulation layer2208 can be ink-jet printed over the entirety of passivation layer 2206(e.g., a blanket deposition). First encapsulation layer 2208 can be anoptically transmissive or transparent layer, through which light emittedfrom display components 2204 can pass. In some examples, a thickness offirst encapsulation layer 2208 is less than a threshold thickness (e.g.,10 microns or less, 12 microns or less, or 14 microns or less, etc.).

A display-noise shield/sensor 2210 can be formed over the firstencapsulation layer 2208, in some examples. In some such examples, alayer of display-noise shield/sensor 2210 can be in direct contact withfirst encapsulation layer 2208. During a manufacturing process ofstack-up 2200, display-noise shield/sensor 2210 is manufactured overfirst encapsulation layer 2208 after layer 2208 has been ink-jet printedover passivation layer 2206. As discussed with respect to later drawingsrelated to display-noise shield/sensor 2210, the shield/sensor can beformed from one or more metal layers, which can be directly formedand/or deposited over the first encapsulation layer 2208. Providing adisplay-noise shield/sensor 2210 in this way can sometimes be referredto herein as “manufacture by on-cell process,” or an in situmanufacturing technique. The process of manufacturing display-noiseshield/sensor using an on-cell process provides numerous advantages overalternative techniques, where a discrete, or semi-discrete componentmanufactured using a different process (e.g., at a different time,location, using different manufacturing equipment, etc.) from theprocess used to manufacture the prior layers (e.g., substrate 2202,display components 2204, passivation layer 2206, and first encapsulationlayer 2208). In some examples, these advantages include the eliminationof alignment and lamination steps associated with aligning the(semi-)discrete component associated with a display-noise shield/sensorto the already-manufactured layers 2202-2208 and using a laminate oradhesive to affix the component associated with the display-noiseshield/sensor to the already-manufactured layers 2202-2208. Theseadvantages of manufacturing display-noise shield/sensor using an on-cellprocess contribute to lower yield losses of the overall stack-up 2200,relative to alternative processes. Additionally or alternatively, insome examples, the thickness of the touch sensor panel can be reducedusing the on-cell process compared with a discrete touch sensorlaminated to the display, thereby reducing the overall thickness of thetouch screen.

Display-noise shield/sensor 2210 can be either a shield and/or a sensor,depending on the implementation. Whether display-noise shield/sensor2210 is a shield or a sensor, shield/sensor 2210 can be manufacturedover first encapsulation layer 2208. As described above, layer 2208 cansometimes be selectively ink-jet printed onto portions of passivationlayer 2206 under which display components 2204 are formed, in someexamples. In such examples, display-noise shield/sensor 2210 is formedonly on those selectively ink-jet printed portions of firstencapsulation layer 2208. In some examples, where display-noiseshield/sensor 2210 is a shield, the shield can include a singleconductive layer (e.g., ITO layer, metal layer) or metal mesh layer. Insome examples, the shield layer can be flooded with conductivematerial(s) (e.g., ITO, metal). In some examples, the shield layer caninclude with a global mesh pattern such that the footprint of thedisplay-noise shield/sensor 2210 can be occupied by an electricallyconnected conductive metal mesh. In some examples, the shield layer caninclude a combination of the metal mesh flooded with a conductivematerial. The conductive materials can help mitigate noise signalsgenerated by display components 2204 from interfering with componentsformed above display-noise shield/sensor 2210 in stack-up 2200. In someexamples, a shield layer including a metal mesh in combination with aflood of conductive material can provide improved isolation comparedwith metal mesh alone and reduced resistivity compared with a flood ofconductive material alone. In such examples, patches of the flood ofconductive material can be disposed between the metal mesh, resulting inthe layer associated with shield/sensor 2210 sometimes referred to as alayer with alternating metal mesh and conductive material portions(e.g., where the conductive material portions are formed or positionedbetween gaps in the metal mesh). In such examples, this combination canbe formed by first forming a metal mesh layer (e.g., by depositingand/or patterning a first conductive material according to a meshpattern), and then forming a flood of conductive material between themesh pattern of the metal mesh layer (e.g., by depositing and/orpatterning a second conductive material according to a patch pattern,aligned to the mesh pattern, where paths of material of the mesh patternare aligned with open paths of the patch pattern). One alternativeprocess to forming the combination can be first forming a flood ofconductive material in patches (e.g., by depositing and/or patterning asecond conductive material according to a patch pattern), and thenforming a metal mesh pattern in spaces between the patches (e.g., bydepositing and/or patterning a first conductive material according to amesh pattern, aligned to the patch pattern, where patches of material ofthe patch pattern are aligned with open sections of the mesh pattern).Another alternative process to forming the combination can be formingthe flood of conductive material as a solid layer first (e.g., directlyover first encapsulation layer 2208), and then subsequently forming ametal mesh pattern over the solid layer of the conductive material.

When the shield layer is formed using two conductive materials in thisway (e.g., a first material for the mesh pattern, and a second materialfor the patch pattern), a first conductive material for the mesh patterncan be different from a second conductive material for the patchpattern. As an example, the first conductive material for the meshpattern can be aluminum (Al), copper (Cu), or any other suitableconductive material for forming a metal mesh in shield layer 2210. Asanother example, the material for the mesh pattern can be a combinationof conductive materials deposited as multiple layers, such as a layer oftitanium (Ti), onto which a layer of aluminum (Al) is deposited, ontowhich a layer of titanium (Ti) is deposited). In some such examples, themesh pattern formed of layers of titanium, aluminum, and titanium can beabove the second conductive material, or below the second conductivematerial. As an example, the second conductive material for the optionalpatch pattern can be ITO, silver (Ag) nanowire, or any other suitabletransparent (or effectively transparent) conductive material for formingpatches that can be formed above, below, or between the metal mesh inshield/sensor 2210 layer. Accordingly, in some examples, the layerassociated with shield/sensor 2210 can be referred to as a metal meshlayer with patches of ITO, silver, or any other suitable conductivematerial for forming patches.

In some examples, instead of a contiguous conductive layer (or metalmesh pattern, or a combination of the two) spanning an entirety of thefootprint of display-noise shield/sensor 2210, a number of conductivesegments can be electrically coupled (e.g., using the same metal or adifferent metal) to form the shield layer. In such examples, thesegments can be aligned to sub-pixel elements of display components2204.

In examples where display-noise shield/sensor 2210 is a sensor, thesensor can include multiple metal layers or metal mesh layers.Conductive segments with some correspondence to row and column touchelectrodes (e.g., of touch sensor 2216) can be formed in one of themetal (mesh) layers of display-noise shield/sensor 2210 to form a sensor(e.g., electrodes of the sensor). In some examples, a contiguous columnelectrode can be formed in a first metal (mesh) layer of display-noiseshield/sensor 2210, with non-contiguous row electrodes also formed inthe first metal (mesh) layer. A second metal (mesh) layer can includebridges that connect the non-contiguous row electrodes in the firstmetal (mesh) layer, in some examples. In some examples, conductivesegments within the metal (mesh) layers of display-noise shield/sensor2210 can have a one-to-one correspondence to row and column touchelectrodes of touch sensor 2216 (e.g., each conductive patch ofdisplay-noise sensor 2210 has a single corresponding touch electrode oftouch sensor 2216 such that the patterning of the electrodes of thedisplay-noise sensor and the touch electrodes of the touch sensor 2216are the same). In some examples, conductive segments within the metal(mesh) layers of display-noise shield/sensor 2210 can have a size basedon respective sizes of row and column touch electrodes of touch sensor2216 (e.g., each conductive patch of display-noise sensor 2210 has thesame or a proportional size to a corresponding touch electrode of touchsensor 2216). In examples where conductive segments within the metal(mesh) layers of display-noise shield/sensor 2210 are smaller thancorresponding row and column touch electrodes of touch sensor 2216,conductive segments within layers of sensor 2210 can be centered about acenter-point of a corresponding touch electrode of touch sensor 2216. Insome examples, conductive segments within the metal (mesh) layers ofdisplay-noise shield/sensor 2210 are aligned to sub-pixel elements ofdisplay components 2204 and/or touch electrode of touch sensor 2216.

Second encapsulation layer 2212 can be formed over display-noiseshield/sensor 2210, in some examples. In some such examples, secondencapsulation layer 2212 can be in direct contact with a layer ofdisplay-noise shield/sensor 2210. Similar to first encapsulation layer2208, second encapsulation layer 2212 can be printed using selectiveprinting, or blanket printing. Second encapsulation layer 2212 can bereferred to as a “printed layer,” when it is deposited over/ontodisplay-noise shield/sensor 2210 using a printing or depositiontechnique, in some examples. Second encapsulation layer 2212 can bedeposited over/onto display-noise shield/sensor 2210 using an ink-jetprinting technique, in some examples. Ink-jet printing techniques cancause layers to be selectively deposited (e.g., deposited over a portionof an underlying layer), or globally/blanket deposited (e.g., depositedover an entirety of the underlying layer), in some examples. In someexamples, second encapsulation layer 2212 can be ink-jet printedselectively over regions of display-noise shield/sensor 2210 under whichdisplay components 2204 are formed. In other examples, secondencapsulation layer 2212 can be ink-jet printed over the entirety ofdisplay-noise shield/sensor 2210 (e.g., a blanket deposition). Secondencapsulation layer 2212 can be an optically transmissive or transparentlayer, through which light emitted from display components 2204 canpass. In some examples, a thickness of second encapsulation layer 2212is less than a threshold thickness (e.g., 10 microns or less, 12 micronsor less, 14 microns or less, etc.).

Dielectric layer 2214 can optionally be formed over second encapsulationlayer 2212 as an isolation layer to isolate display-noise shield/sensor2210 from touch sensor 2216. In some examples, if one or more metallayers of display-noise shield/sensor 2210 is flooded or provided with aglobal metal mesh, a high parasitic capacitance can develop betweenrow/column electrodes of touch sensor 2216 and display-noiseshield/sensor 2210. In such examples, this high capacitance (referred toas C_(M2_M4) in the context of FIG. 29 ), can result in reducedbandwidth for touch signal sensing by touch sensor 2216. In someexamples, a thickness of dielectric layer 2214 is less than a thresholdthickness (e.g., 3 microns or less, 5 microns or less, 7 microns orless, etc.).

Touch sensor 2216 can be formed over second encapsulation layer 2212and/or dielectric layer 2214 (e.g., when dielectric layer 2214 isincluded in stack-up 2200). Touch sensor 2216 can have metal patternsthat are aligned to display components 2204 (and to display-noiseshield/sensor 2210) so that the metal patterns of touch sensor 2216 donot interfere with, or obstruct light emitted by display components2204. In some examples, touch sensor 2216 can be manufactured using anon-cell process over second encapsulation layer 2212 and/or dielectriclayer 2214. In other examples, touch sensor 2216 can be manufacturedseparately (e.g., at a prior time to manufacturing stack-up 2200) as adiscrete or semi-discrete component, and can subsequently be transferredto its position within stack-up 2200 after the manufacture of precedinglayers (e.g., layers 2202-2214). In some examples,

Polarization layer 2218 can be formed over touch sensor 2216, and caninclude a material that selectively filters light so that only a certainpolarization of light can be transmitted through the material. In someexamples, a thickness of polarization layer 2218 can be between 10 and150 microns, or between 30 and 80 microns in other examples. In someexamples, a thickness of polarization layer 2218 is less than athreshold thickness (e.g., 50 microns or less, 100 microns or less,etc.).

Adhesive layer 2220 can be formed over polarization layer, and caninclude an optically clear/transparent material that allows light to betransmitted through it. In some examples, a thickness of adhesive layer2220 can be between 10 and 80 microns, or between 35 and 55 microns inother examples. In some examples, a thickness of adhesive layer 2220 isless than a threshold thickness (e.g., 30 microns or less, 50 microns orless, 70 microns or less, etc.).

Cover layer 2222 can be formed over adhesive layer 2220, and can includea glass or crystal layer. In some examples, a thickness of cover layer2222 can be between 60 and 120 microns, or between 75 and 105 microns inother examples. In some examples a thickness of cover layer 2222 is lessthan a threshold thickness (e.g., 75 microns or less, 95 microns orless, 115 microns or less, etc.).

FIG. 23 illustrates example layers of a display-noise sensor 2210Aformed on a printed layer of a touch screen stack-up according toexamples of the disclosure. As described in connection with the generaldisplay-noise sensor 2210 of FIG. 22 , display-noise sensor 2210A can beformed on first encapsulation layer 2208. In some examples, firstencapsulation layer 2208 is deposited using ink-jet printing and forms asubstantially flat surface upon which metal layer(s) can be formed(e.g., points on the surface of first encapsulation layer 2208 are allwithin a 5% range of a target level height for the first encapsulationlayer within stack-up 2200).

First metal layer 2302 can be formed over the first encapsulation layer2208. In some examples, display-noise sensor 2210A can be formed usingan on-cell manufacturing technique (e.g., by forming sensor 2210Adirectly on first encapsulation layer 2208 as part of the samemanufacturing process). Forming a display-noise sensor can requireforming multiple metal layers separated by an interlayer dielectriclayer between them and connected by vias through the interlayerdielectric layer, in some examples (e.g., metal layers 2302 and 2306separated by interlayer dielectric layer 2304 of FIG. 23 ).

In some examples, the on-cell manufactured display-noise sensor 2210Acan be formed by first forming a first metal layer 2302 over the firstencapsulation layer 2208, followed by forming an interlayer dielectriclayer 2304, and finally forming a second metal layer 2306. In someexamples, a thickness of first metal layer 2302 can be between 0.4 and 1micron, or between 0.5 and 0.9 microns in other examples. In someexamples, a thickness of first metal layer 2302 can be less than athreshold thickness (e.g., 0.4 microns or less, 0.6 microns or less, 0.8microns or less, etc.). In some examples, a thickness of interlayerdielectric layer 2304 can be between 1 and 2.2 microns, or between 1.3and 1.9 microns. In some examples, a thickness of interlayer dielectriclayer 2304 can be less than a threshold thickness (e.g., 1.4 microns orless, 1.6 microns or less, 1.8 microns or less, etc.). In some examples,a thickness of second metal layer 2306 can be between 0.4 and 1 micron,or between 0.5 and 0.9 microns in other examples. In some examples, athickness of second metal layer 2306 can be less than a thresholdthickness (0.4 microns or less, 0.6 microns or less, 0.8 microns orless, etc.).

In some examples, the first and second metal layers 2302 and 2306 can beused to form row noise-sensor electrodes and column noise-sensorelectrodes of display-noise sensor 2210A, corresponding to row andcolumn touch electrodes of touch sensor 2216. As an example, rownoise-sensor electrodes and column noise-sensor electrodes in first andsecond metal layers 2302 and 2306 can form a mutual-capacitance typetouch sensor, or a self-capacitance type touch sensor. In such examples,interlayer dielectric layer 2304 between the two metal layers 2302/2306can be patterned with vias, to allow interconnection between at leastone portion of one metal layer with at least one portion of the othermetal layer. As an example, row noise-sensor electrodes can be formed infirst metal layer 2302, and column noise-sensor electrodes can be formedin second metal layer 2306. Alternatively, column noise-sensorelectrodes can be formed in first metal layer 2302, and row noise-sensorelectrodes can be formed in second metal layer 2306. As another example,both row noise-sensor electrodes and column noise-sensor electrodes canbe formed in first metal layer 2302, and second metal layer 2306 can beused to form conductive bridges to connect any discontinuous noisesensor electrodes in the first metal layer. Alternatively, both rownoise-sensor electrodes and column noise-sensor electrodes can be formedin second metal layer 2506, and first metal layer 2502 can be used toform conductive bridges to connect any discontinuous noise sensorelectrodes in the second metal layer. In examples where both rownoise-sensor electrodes and column noise-sensor electrodes are formed ina single metal layer of the first/second metal layers, the columnnoise-sensor electrodes may have a contiguous shape such as a solid bar(e.g., a contiguous metal mesh pattern), and the row noise-sensorelectrodes may have a non-contiguous shape such as a plurality ofsegments (e.g., a stripe pattern of non-contiguous metal mesh segments,adjacent to one or more column electrodes). In such examples, dielectriclayer 2304 can be patterned with vias, that allow for metalinterconnections between the non-contiguous segments of row noise-sensorelectrodes in one of the metal layers (e.g., first metal layer 2302),and conductive structures in the other metal layer (e.g., second metallayer 2306). In such examples, conductive structures in the other (e.g.,second) metal layer can include conductive bridge structures, thatextend at least the length of separation between non-contiguous rownoise-sensor electrode segments in the metal layer containing thecontiguous column noise-sensor electrodes and the non-contiguous rownoise-sensor electrode segments (e.g., first metal layer). By way of thevias formed by patterning of interlayer dielectric layer 2304, bridgestructures in the other metal layer can electrically couple thenon-contiguous row noise-sensor electrode segments, and allow thesegments to function similar to a continuous row electrode along theirlength.

FIG. 24 illustrates an example display-noise shield formed on a printedlayer of a touch screen stack-up according to examples of thedisclosure. As described in connection with the general display-noisesensor 2210 of FIG. 22 , display-noise shield 2210B can be formed onfirst encapsulation layer 2208. In some examples, first encapsulationlayer 2208 is deposited using ink-jet printing, and forms asubstantially flat surface upon which metal layers can be formed.

Metal layer 2402 can be formed over the first encapsulation layer 2208.In some examples, display-noise shield 2210B can be formed using anon-cell manufacturing technique (e.g., by forming shield 2210B directlyon first encapsulation layer 2208 as part of the same manufacturingprocess). Forming a display-noise shield can require forming a metallayer 2402 and including a dielectric shield within stack-up 2200 (e.g.dielectric layer 2214) to reduce parasitic capacitances with metal layer2402.

In some examples, the on-cell manufactured display-noise shield 2210Bcan be formed by first forming a metal layer 2402 over the firstencapsulation layer 2208, followed by forming a second encapsulationlayer 2212 over metal layer 2402. In examples where metal layer 2402 isflooded or provided with a global metal mesh, a high parasiticcapacitance can develop between row/column electrodes of touch sensor2216 and display-noise shield/sensor 2210. In such examples, this highcapacitance (sometimes referred to as C_(M2_M4) in the context of FIG.29 ), can result in results in very low bandwidth for touch signalsensing by touch sensor 2216. An optional dielectric layer 2214 can beprovided above second encapsulation layer 2212 to isolate touch sensor2216 from parasitic capacitances with metal layer 2402. In someexamples, a thickness of metal layer 2402 can be between 0.4 and 1micron, or between 0.5 and 0.9 microns in other examples. In someexamples, a thickness of metal layer 2402 can be less than a thresholdthickness (0.4 microns or less, 0.6 microns or less, 0.8 microns orless, etc.).

Metal layer 2402 can be flooded with metal, or be filled with a globalmetal mesh pattern, such that the entire footprint of the display-noiseshield/sensor 2210 can be occupied by a conductive metal (mesh), thatcan help mitigate noise signals generated by display components 2204from interfering with components formed above display-noiseshield/sensor 2210 in stack-up 2200. In some examples, metal layer 2402can be filled with a combination of a flood of conductive material and ametal mesh to provide improved insulation (e.g., compared with meshalone) and reduced resistivity (compared to a flood of conductivematerial alone). In some such examples, patches of the flood ofconductive material can be disposed between the metal mesh. Sometimesmetal layer 2402 can be referred to as having alternating metal mesh andconductive material portions (e.g., where the conductive materialportions are formed or positioned between gaps in the metal mesh). Insome such examples, the combination can be formed by first forming ametal mesh layer (e.g., by depositing and/or patterning a firstconductive material according to a mesh pattern) and then forming aflood of conductive material between the mesh pattern of the metal meshlayer (e.g., by depositing and/or patterning a second conductivematerial according to a patch pattern, aligned to the mesh pattern,where paths of material of the mesh pattern are aligned with open pathsof the patch pattern). Alternatively, the order of material formationcan be reversed (e.g., as described above in connection withdisplay-noise shield/sensor 2210 of FIG. 22 ). One alternative processto forming the combination can be first forming a flood of conductivematerial in patches, and then forming a metal mesh pattern in spacesbetween the patches. Another alternative process to forming thecombination can be forming the flood of conductive material as a solidlayer first, and then subsequently forming a metal mesh pattern over thesolid layer of the conductive material.

FIG. 25 illustrates an example touch sensor of a touch screen stack-upaccording to examples of the disclosure. In some examples, FIG. 25 canshow a sub-stack 2500 of stack-up 2200 shown/described by FIG. 22 .Specifically, FIG. 25 can show a sub-stack 2500 corresponding to touchsensor 2216 of FIG. 22 , when touch sensor 2216 is manufactured/formedaccording to an on-cell process, or is manufactured in situ, accordingto some examples. As described above in connection with the manufactureof display-noise shield/sensor 2210, manufacturing touch sensor 2216using an on-cell process provides similar advantages over alternativearrangements (e.g., arrangements where a discrete, or semi-discretetouch sensor manufactured using a different process is transferred tothe manufacture process used to form layers 2202-2214 of FIG. 22 ). Insome examples, these advantages include the elimination of alignment andlamination/adhesion steps associated with aligning the (semi-)discretetouch sensor to the already-manufactured layers 2202-2214 and using alaminate or adhesive to affix the (semi-)discrete touch sensor to saidalready-manufactured layers 2202-2214. These advantages of manufacturingthe touch sensor using an on-cell process contribute to lower yieldlosses of the overall stack-up 2200, relative to alternative processes.Moreover, by eliminating alignment steps necessitated by mergingdifferent manufacturing processes (e.g., when transferring asemi-discrete touch sensor to on-cell manufactured layers 2202-2214),touch accuracy associated with sensed signals of touch sensor 2216 canbe improved. Because touch sensor 2216 is aligned by virtue of beingmanufactured using an on-cell process (sometimes referred to as being“process-aligned”), row touch electrodes and column touch electrodes oftouch sensor 2216 can be substantially aligned with corresponding rownoise-sensing electrodes and column noise-sensing electrodes ofdisplay-noise shield/sensor 2210 (e.g., row and column touch electrodesmay overlay corresponding row and column noise-sensing electrodes withina 5% deviation from a target centered/aligned position within stack-up2200). Additionally, touch sensor 2216 being process-aligned can improveor optimize the alignment of row touch electrodes and column touchelectrodes of the touch sensor with pixels and/or sub-pixels of displaycomponents 2204.

As illustrated in FIG. 25 , touch sensor 2216 can be formed overdielectric layer 2214 and/or second encapsulation layer 2212. Asdescribed in connection with stack-up 2200 of FIG. 22 , secondencapsulation layer 2212 can be deposited according to a blanketdeposition process, or according to a selective deposition process(e.g., ink-jet printing). In some examples, depositing secondencapsulation layer 2212 according to a blanket deposition process canresult in a surface of the second encapsulation layer being planar(e.g., level, or even). In some examples, the layers of touch sensor2216 can be formed directly on the planar surface of secondencapsulation layer 2212. In some examples, a dielectric layer 2214 maybe formed over the second encapsulation layer 2212. Dielectric layer2214 can sometimes be called an “isolation dielectric layer” or even a“thick dielectric layer,” in reference to its separating touch sensor2216 from display-noise shield/sensor 2210, and from display components2204 (e.g., components formed below touch sensor 2216). In someexamples, dielectric layer 2214 can be called “thick” because of itsthickness being relatively larger than the thickness of other dielectriclayers (such as those of display-noise sensor 2210A) in stack-up 2200 ofFIG. 22 . In some examples, a thickness of dielectric layer 2214 can bebetween 1 and 6 microns, or can be between 2 and 5 microns in otherexamples. In some examples, a thickness of dielectric layer 2214 can beless than a threshold thickness (e.g., 2 microns or less, 5 microns orless, 8 microns or less, etc.). Separating touch sensor 2216 fromcomponents formed below it (e.g., by the inclusion of dielectric layer2214) reduces the impact of noise and/or interference from saidcomponents, and additionally reduces the parasitic capacitances betweenthe touch sensor and said components, in some examples.

The on-cell manufactured touch sensor 2216 can be formed by firstforming a first metal layer 2502 over the second encapsulation layerand/or dielectric layer 2214, followed by forming an interlayerdielectric layer 2504, and finally forming a second metal layer 2506. Insome examples, the first and second metal layers 2502 and 2506 can beused to form row touch electrodes and column touch electrodes of a touchsensor. As an example, row touch electrodes and column touch electrodesin first and second metal layers 2502 and 2506 can form amutual-capacitance type touch sensor, or a self-capacitance type touchsensor. In such examples, interlayer dielectric layer 2504 between thetwo metal layers 2502/2506 can be patterned with vias, to allowinterconnection between at least one portion of one metal layer with atleast one portion of the other metal layer. As an example, row touchelectrodes can be formed in first metal layer 2502, and column touchelectrodes can be formed in second metal layer 2506. Alternatively,column touch electrodes can be formed in first metal layer 2502, and rowtouch electrodes can be formed in second metal layer 2506. As anotherexample, both row touch electrodes and column touch electrodes can beformed in first metal layer 2502, and second metal layer 2506 can beused to form conductive bridges to connect any discontinuous touchelectrodes in the first metal layer. Alternatively, both row touchelectrodes and column touch electrodes can be formed in second metallayer 2506, and first metal layer 2502 can be used to form conductivebridges to connect any discontinuous touch electrodes in the secondmetal layer. In examples where both row touch electrodes and columntouch electrodes are formed in a single metal layer of the first/secondmetal layers, the column electrodes may have a contiguous shape such asa solid bar (e.g., a contiguous metal mesh pattern), and the rowelectrodes may have a non-contiguous shape such as a plurality ofsegments (e.g., a stripe pattern of non-contiguous metal mesh segments,adjacent to one or more column electrodes). In such examples, dielectriclayer 2504 can be patterned with vias, that allow for metalinterconnections between the non-contiguous segments of row electrodesin one of the metal layers (e.g., first metal layer 2502), andconductive structures in the other metal layer (e.g., second metal layer2506). In such examples, conductive structures in the other (e.g.,second) metal layer can include conductive bridge structures, thatextend at least the length of separation between non-contiguous rowtouch electrode segments in the metal layer containing the contiguouscolumn touch electrodes and the non-contiguous row touch electrodesegments (e.g., first metal layer). By way of the vias formed bypatterning of interlayer dielectric layer 2504, bridge structures in theother metal layer can electrically couple the non-contiguous row touchelectrode segments, and allow the segments to function similar to acontinuous row electrode along their length. In some examples, the touchsensor can be implemented according to the touch electrodes (androuting) patterns described with respect to FIGS. 5-21 .

FIG. 26 illustrates an example transfer-type touch sensor of a touchscreen stack-up according to examples of the disclosure. In someexamples, FIG. 26 can show a sub-stack 2600 of stack-up 2200shown/described by FIG. 22 . In contrast to the arrangement describedabove in connection with FIG. 25 , touch sensor 2216 as illustrated byFIG. 26 is not manufactured using on-cell processes. Instead, touchsensor 2216 of FIG. 26 represents a discrete or semi-discrete componentmanufactured using a different process than the manufacturing processused to form layers 2202-2214 of FIG. 22 . In other words, touch sensor2216 represents a component that is manufactured at a different time, adifferent location, and/or using a different manufacturing process,relative to layers 2202-2214 of FIG. 22 (e.g., the preceding layers ofstack-up 2200).

Similar to the arrangement of FIG. 25 , touch sensor 2216 of FIG. 26includes a first metal layer 2602, an interlayer dielectric layer 2604,and a second metal layer 2606. These layers may be equivalent tocorresponding layers 2502, 2504, and 2506 of FIG. 25 , except that thealignment from lamination may be reduced compared with theprocess-alignment with layers 2202-2214 of FIG. 22 resulting fromon-cell processes. Because touch sensor 2216 of FIG. 26 is manufacturedusing a different process than preceding layers of a stack-up, the touchsensor can sometimes be referred to as a “transfer-type” touch sensor.With a transfer-type touch sensor, as illustrated by FIG. 26 , some ofthe advantages of on-cell processes are not available, requiring carefulalignment and lamination/adhesion steps to integrate touch sensor 2216with layers 2202-2214 of stack-up 2200 of FIG. 22 . These additionalalignment and lamination/adhesion steps complicate the manufacture ofstack-up 2200, and are prone to error, in some examples. Examples oferror in alignment can include mis-aligning touch sensor 2216 relativeto display-noise shield/sensor 2210 and/or display components 2204, suchthat rows and columns formed in the metal layers of touch sensor 2216are not substantially aligned with corresponding structures inshield/sensor 2210 and/or display components 2204. Such an error canreduce touch sensor accuracy, and/or result in additional yield loss.Examples of error in lamination/adhesion can include partial/incomplete,or insufficient adhesion of touch sensor 2216 to the remainder ofstack-up 2200 (e.g., preceding layers 2202-2214). Specifically,transfer-type touch sensor 2216 of FIG. 26 can be laminated/adhered tothe remainder of stack-up 2200 by adhesive layer 2610. However, partialand/or incomplete adhesion between adhesive layer 2610 and dielectriclayer 2214 or second encapsulation layer 2212 can result in insufficientanchoring of touch sensor 2216 to stack-up 2200. Insufficient anchoringof touch sensor 2216 to stack-up 2200 can result in future misalignmentof touch sensor 2216 relative to stack-up 2200 (e.g., by movement oftouch sensor 2216), or inconsistent performance of touch sensor 2216during operation of a device containing stack-up 2200 (e.g., due tostrain/force on touch sensor 2216 that causes it to move while thedevice is in use). Additionally, because touch sensor 2216 of FIG. 26 isnot formed using on-cell processes, but is instead manufactured using adifferent process, touch sensor substrate(s) 2608 may be included withinstack-up 2200 of FIG. 22 , and can correspond to a base substrate uponwhich the layers 2602-2606 are formed (e.g., during the separatemanufacture of transfer-type touch sensor 2216).

FIG. 27 illustrates exemplary readout terminals of a touch sensor and apixel-aligned display-noise sensor of a touch screen stack-up accordingto examples of the disclosure. FIG. 27 illustrates a simplified stack-uprelative to 2200 of FIG. 22 , only illustrating display components 2204(represented here as pixels in an array, each with multiple sub-pixels),a metal layer of display-noise sensor 2210A (e.g., second metal layer2306 of FIG. 23 ), and a metal layer of touch sensor 2216 (e.g., secondmetal layer 2506 of FIG. 25 , or 2606 of FIG. 26 ). Starting from thebottom of the simplified stack-up, display components 2204 can be usedto display text, images, videos, or other information to a user, and cando so by modifying signals input to the display to causecorresponding/desired changes to outputs of the display components 2204themselves. When output values of pixels in display components 2204change during normal operation of an electronic device, the changingpixel output values can generate associated noise signals that areusually localized to a vicinity of the display components 2204 thatchanged.

Display-noise sensor 2210A is illustrated above display components 2204,and can be formed over first encapsulation layer 2208, as describedabove in connection with FIGS. 22 and 23 . FIG. 27 illustratesdisplay-noise sensor 2210A as a single metal layer, corresponding toembodiments in which both row noise-sensor electrodes and columnnoise-sensor electrodes are formed in a single metal layer (e.g., secondmetal layer 2306 of FIG. 23 ). In such examples, another metal layer(e.g., first metal layer 2302) can be used to form interconnectionsbetween discontinuous row and/or column noise sensor electrode segments(e.g., in second metal layer 2306). However, this is merelyillustrative, and display-noise sensor 2210A can also have rownoise-sensor electrodes and column noise-sensor electrodes formed indifferent respective metal layers. Row noise-sensor electrodes thatextend in a first direction over corresponding segments of displaycomponents 2204 can be sensitive to electrical noise generated bychanges to output values of underlaying display components 2204 alongthe first direction. A connection point of a row noise-sensor electrodeof display-noise sensor 2210A can be labeled by the terminal B1, andread out at a readout circuit (e.g., 2900 of FIG. 29 ). Similarly,column noise-sensor electrodes that extend in a second direction,different from the first direction, over corresponding segments ofdisplay components 2204 can be sensitive to electrical noise generatedby changes to output values of underlaying display components 2204 alongthe second direction. A connection point of a column noise-sensorelectrode of display-noise sensor 2210A can be labeled by the terminalB2, and read out at a readout circuit. Metal used to form rownoise-sensor electrodes and column noise-sensor electrodes indisplay-noise sensor 2210A can be patterned to be substantially alignedwith sub-pixel components of display components 2204, such that metal indisplay-noise sensor 2210A does not optically interfere with lighttransmitted from display components 2204 (e.g., pattern features of rowand column noise-sensor electrodes may overlay corresponding sub-pixeldisplay components within a 5% deviation from a target centered/alignedposition within stack-up 2200).

Touch sensor 2216 is illustrated above display-noise sensor 2210A(opposite side of the display-noise sensor from the display), and can beformed over dielectric layer 2214 and/or second encapsulation layer2212, as described above in connection with FIGS. 22 and 25 . Touchsensor 2216 is illustrated as a single metal layer, corresponding toembodiments in which both row touch electrodes and column touchelectrodes are formed in a single metal layer (e.g., second metal layer2506 of FIG. 25 ). In such examples, another metal layer (e.g., firstmetal layer 2502) can be used to form interconnections betweendiscontinuous row and/or column touch electrode segments (e.g., insecond metal layer 2506). However, this is merely illustrative, andtouch sensor 2216 can also have row noise-sensor electrodes and columnnoise-sensor electrodes formed in different respective metal layers. Rowtouch electrodes that extend in a first direction over correspondingsegments of display components 2204 can be sensitive to electrical noisegenerated by changes to output values of underlaying display components2204 along the first direction. These row touch electrodes can alsoextend over a corresponding row noise-sensor electrode of display-noisesensor 2210A. A connection point of a row touch electrode of touchsensor 2216 can be labeled by the terminal A1, and read out at a readoutcircuit in parallel with a corresponding signal from a row noise-sensorelectrode labeled by the terminal B1. Similarly, column touch electrodesthat extend in a second direction, different from the first direction,over corresponding segments of display components 2204 can be sensitiveto electrical noise generated by changes to output values of underlayingdisplay components 2204 along the second direction. These column touchelectrodes can also extend over a corresponding column noise-sensorelectrode of display-noise sensor 2210A. A connection point of a columntouch electrode of touch sensor 2216 can be labeled by the terminal A2,and read out at a readout circuit in parallel with a correspondingsignal from a column noise-sensor electrode labeled by the terminal B2.Metal used to form row/column touch electrodes in touch sensor 2216 canbe patterned to be substantially aligned with sub-pixel components ofdisplay components 2204, such that metal in touch sensor 2216 does notoptically interfere with light transmitted from display components 2204(e.g., pattern features of row and column touch electrodes may overlaycorresponding sub-pixel light-emitting display components within a 5%deviation from a target centered/aligned position within stack-up 2200).

Each row touch electrode of touch sensor 2216 can overlay acorresponding row noise-sensor electrode of display-noise sensor 2210A,in some examples. Each corresponding pair of row touch electrode and rownoise-sensor electrode can overlay a corresponding row of display pixelsof display components 2204, and can be sensitive to electrical noisegenerated by changes to output values of underlaying display components2204, in some examples. To mitigate the influence of electrical noisefrom the display components 2204, display-noise signals fromrows/columns of display-noise sensor 2210A (e.g., signals read out fromterminals B1/B2) can be read out in parallel with corresponding touchdetection signals from rows/columns of touch sensor 2216 (e.g., signalsread out from terminals A1/A2), by a readout circuit, in some examples.In some examples, the signals B1/B2 read out from display-noise sensor2210A and the signals A1/A2 read out from touch sensor 2216 cancorrespond to rows and/or columns of display-noise sensor 2210A that arealigned, and overlapping with rows and/or columns of touch sensor 2216.Reading out display-noise signals from B1/B2 in parallel with touchdetection signals from A1/A2 allows a readout circuit to subtractdisplay-noise signals from the touch detection signals, therebygenerating noise-corrected touch detected signals with a mitigatedcontribution of display-noise signals to the touch detection signals. Insome examples, such an arrangement can result in improved accuracy andrepeatability in measuring touch input from a user based on thenoise-corrected touch detection signals.

In some examples, particular rows and columns of display-noise sensor2210A can be combined into larger regions that partition the area overdisplay components 2204 (or the area under touch sensor 2216). In suchexamples, particular rows and columns can be combined by “ganging,” orelectrically connecting, outputs of the particular rows and columns sothe larger region formed by the particular rows and columns incombination can be read out at a single time (or, at a single terminal).Alternatively, the particular rows and columns can be read outsequentially (or, at their respective terminals), and then combined, toproduce an output corresponding to a noise signal at the larger regionformed by the particular rows and columns in combination. Whenparticular row noise-sensor electrodes and column noise-sensorelectrodes of display-noise sensor 2210A are combined into largerregions in this way, each region of display-noise sensor 2210A can besensitive to electrical noise generated by changes to output values ofcorresponding regions of display components 2204 below. In turn, theregions formed by combined row noise-sensor electrodes and columnnoise-sensor electrodes can be formed below corresponding regions oftouch sensor 2216. In such examples, signals read out from a particularregion of display-noise sensor 2210A can be read out in parallel withcorresponding touch detection signals from rows/columns of touch sensor2216 corresponding to signals within a corresponding region (e.g., a rowtouch electrode or column touch electrode above the particular region ofdisplay-noise sensor 2210A). In some examples, these signals (e.g., froma region of display-noise sensor 2210A, and a corresponding region oftouch sensor 2216) can be read out by a common readout circuit(described below, in connection with FIG. 29 ). Similar to the approachwhen a single row/column noise-sensor electrode and a single row/columntouch electrode are read out by a common readout circuit, when firstsignals from a region of noise-sensor electrodes of display-noise sensor2210A and second signals from a corresponding region of touch sensor2216 are read out, the first signals can be subtracted from the secondsignals to generate a readout value corresponding to the touch signalswithout the noise contribution/influence of display components 2204(e.g., without display-noise).

This approach, of partitioning display-noise sensor 2210A into largerregions that extend beyond a single row or a single column, can beextended to combine all the row noise-sensor electrodes and columnnoise-sensor electrodes of display-noise sensor 2210A to generate aglobal readout, corresponding to a noise signal at the entiredisplay-noise sensor 2210A. Similar to the approach when a region ofmultiple row/column noise-sensor electrodes and a corresponding regionof row/column touch electrode are read out by a common readout circuit,when first signals corresponding to the entire display-noise sensor2210A and second signals from any region of touch sensor 2216 are readout, the first signals can be subtracted from the second signals togenerate a readout value corresponding to the touch signals without thenoise contribution/influence of display components 2204 (e.g., withoutdisplay-noise).

FIG. 28 illustrates exemplary readout terminals of a touch sensor and adisplay-noise shield of a touch screen stack-up according to examples ofthe disclosure. FIG. 28 illustrates a simplified stack-up relative to2200 of FIG. 22 , only illustrating display components 2204 (representedhere as pixels in an array, each with multiple sub-pixels), a metallayer of display-noise shield 2210B (e.g., metal layer 2402 of FIG. 24), and a metal layer of touch sensor 2216 (e.g., second metal layer 2506of FIG. 25 , or 2606 of FIG. 26 ). Similar to the description above inconnection with FIG. 27 , when output values of pixels in displaycomponents 2204 change during normal operation of an electronic device,the changing pixel output values can generate associated noise signalsthat are usually localized to a vicinity of the display components 2204that changed.

Display-noise shield 2210B is illustrated above display components 2204,and can be formed over first encapsulation layer 2208, as describedabove in connection with FIGS. 22 and 23 . FIG. 28 illustratesdisplay-noise shield 2210B as a single metal layer, corresponding toembodiments in which a global mesh is formed across metal layer 2402 (ofFIG. 24 ), thereby covering an entirety of the display components 2204.In some examples, the global mesh associated with display-noise shield2210B can be partitioned into non-contiguous shield segments. In suchexamples, multiple connection points corresponding to the multipleshield segments can be provided. However, in the example illustrated byFIG. 28 , a connection point of the entire display-noise shield 2210Bcan be labeled by the terminal C, and as illustrated by FIG. 30 , theterminal C can be coupled to a ground voltage, thereby biasing theentire shield 2210B at a fixed voltage level. Metal used to formdisplay-noise shield electrode(s) of display-noise shield 2210B can bepatterned to be substantially aligned with sub-pixel components ofdisplay components 2204, such that metal in display-noise shield 2210Bdoes not optically interfere with light transmitted from displaycomponents 2204 (e.g., pattern features of a display-noise shield mayoverlay corresponding sub-pixel display components within a 5% deviationfrom a target centered/aligned position within stack-up 2200).

Touch sensor 2216 is illustrated above display-noise shield 2210B, andcan be formed over dielectric layer 2214 and/or second encapsulationlayer 2212, as described above in connection with FIGS. 22 and 25 . Dueto the high capacitance between the global mesh of metal layer 2402 andtouch sensor 2216, sometimes an optional dielectric layer 2214 isprovided between display-noise shield 2210B and touch sensor 2216 insome examples. As mentioned above in connection with FIG. 22 , includingdielectric layer 2214 between display-noise shield 2210B and touchsensor 2216 can improve isolation between those layers of stack-up 2200,thereby improving touch sensing performance, accuracy, andrepeatability. Touch sensor 2216 is illustrated as a single metal layer,corresponding to embodiments in which both row touch electrodes andcolumn touch electrodes are formed in a single metal layer (e.g., secondmetal layer 2506 of FIG. 25 ). Similar to FIG. 27 , touch sensor 2216 isillustrated having row and column touch electrodes. A connection pointof a row touch electrode of touch sensor 2216 can be labeled by theterminal A1, and read out at a readout circuit. A connection point of acolumn touch electrode of touch sensor 2216 can be labeled by theterminal A2, and read out at a readout circuit. Metal used to formrow/column touch electrodes in touch sensor 2216 can be patterned to besubstantially aligned with sub-pixel components of display components2204, such that metal in touch sensor 2216 does not optically interferewith light transmitted from display components 2204 (e.g., patternfeatures of row and column touch electrodes may overlay correspondingsub-pixel display components within a 5% deviation from a targetcentered/aligned position within stack-up 2200).

Each row touch electrode of touch sensor 2216 can overlay display-noiseshield 2210B, in some examples. As signals are read out fromrows/columns of touch sensor 2216, display-noise shield 2210B can beactively biased to a particular voltage level during touch sensingoperations of touch sensor 2216, in some examples. In such examples,terminal C of display-noise shield 2210B can receive one or morestimulation signals (e.g., a voltage that varies in time) during thetouch sensing operations of touch sensor 2216, or can be biased to aground voltage (or, any other suitable fixed voltage level). In someexamples, such an arrangement can result in improved accuracy andrepeatability in measuring touch input from a user based on thenoise-corrected touch detection signals, by applying one or more biasvoltages to display-noise shield 2210B at least during touch sensingoperations of touch sensor 2216, thereby shielding row/column touchelectrodes of the touch sensor from electrical interference generated bydisplay components 2204 (e.g., display-noise).

FIG. 29 illustrates exemplary readout circuitry for a touch sensor and adisplay-noise sensor of a touch screen stack-up according to examples ofthe disclosure. Readout circuit 2900 (also referred to herein as sensingcircuitry) can represent an exemplary circuit schematic that modelsparasitic/undesired capacitances between components of stack-up 2200 ofFIG. 22 as well as terminal inputs corresponding to connection pointsfor rows/columns of touch sensor 2216 (e.g., A1/A2), and rows/columns ofdisplay-noise sensor 2210A (e.g., B1/B2). An overall function of readoutcircuit 2900 can be to output a voltage V_(OUT) proportional to adifference between a voltage at positive input 2904 and negative input2902. V_(OUT) is therefore proportional to a difference between a signalfrom connection points B1/B2 corresponding to rows/columns ofdisplay-noise sensor 2210A, and a signal from connection points A1/A2corresponding to rows/columns of touch sensor 2216. V_(OUT) thereforerepresents a signal based on the positive input 2904 and negative input2902, that can be used to determine a value of the touch signal detectedby touch sensor 2216 at connection points A1/A2, minus a noise signaldetected by display-noise sensor 2210A at connection points B1/B2.

As described above in connection with FIGS. 27 , display-noise sensor2210A can sometimes be partitioned into regions by combining outputvalues from particular row noise-sensor electrodes and/or columnnoise-sensor electrodes, in some examples. In other examples,display-noise sensor 2210A can be used to generate a global readout thatcombines output values from all the row noise-sensor electrodes and allthe column noise-sensor electrodes. Though not illustrated by FIG. 29 ,these signals can also be provided at positive input 2904.

In some examples, readout circuit 2900 can perform similar functions totouch sensor circuits 300 and 350 of FIGS. 3A and 3B. As describedabove, touch sensor circuits 300/350 can produce an output Vocorresponding to a single-ended readout of a row/column of touch sensor2216 (e.g., a touch electrode signal readout), in some examples.Similarly, touch sensor circuits 300/350 can be coupled to rows/columnsof display-noise sensor 2210A to produce single-ended readouts ofrows/columns of display-noise sensor 2210A, in some examples. In suchexamples, an output from a touch sensor circuit 300/350 coupled to arow/column of display-noise sensor 2210A can be subtracted from anoutput from a touch sensor circuit 300/350 coupled to a row/column oftouch sensor 2216 to obtain a difference value comparable orproportional to the output voltage VOUT of readout circuit 2900.

A voltage source labeled V_(NOISE) (CATHODE) represents a noisecontribution from display components 2204 to other components ofstack-up 2200 of FIG. 22 , in some examples. Capacitor C_(M2_C)represents a parasitic or unwanted capacitance between the cathode(e.g., display components 2204) and a metal layer called M2 (e.g., ametal layer corresponding to display-noise shield/sensor 2210). Inexamples where display-noise shield/sensor 2210 is display-noise sensor2210A, metal layer M2 can correspond to second metal layer 2306 of FIG.23 . In examples where display-noise shield/sensor 2210 is display-noiseshield 2210B, metal layer M2 can correspond to metal layer 2402 of FIG.24 . Positive input 2904 is connected to display-noise shield/sensor2210, and can therefore be subject to the C_(M2_C) capacitance (asillustrated by their connection in FIG. 29 ). Capacitor CM_(4_C)represents a parasitic or unwanted capacitance between the cathode(e.g., display components 2204) and a metal layer called M4 (e.g., ametal layer corresponding to row/column electrodes of touch sensor2216). In examples where row and column electrodes are formed in asingle layer, closest to the user (e.g., closest to cover layer 2222 ofFIG. 22 ), metal layer M4 can correspond to second metal layer 2506.Negative input 2902 is connected to touch sensor 2216, and can thereforebe subject to the C_(M4_C) capacitance (as illustrated by theirconnection in FIG. 29 ). Capacitance C_(M4_M2) represents a parasitic orunwanted capacitance between metal layers M2 and M4, and is shownconnected between positive input 2904 and negative input 2902 because itcan subject the two layers those input can be connected to, in someexamples.

Positive input 2904 is shown connected to differential amplifier 2906via resistor R_(M2), which can represent an inherent resistanceassociated with the metal layer called M2 described above.Alternatively, R_(M2) can represent an input resistor to a positiveterminal of differential amplifier 2906, and can have a particular,pre-defined value. Negative input 2902 is shown connected todifferential amplifier 2906 via resistor R_(M4), which can represent aninherent resistance associated with the metal layer called M4 describedabove. Alternatively, R_(M4) can represent an input resistor to anegative terminal of differential amplifier 2906, and can have aparticular, pre-defined value. R_(BIAS) can represent a resistorconnecting a bias voltage VBIAS to a positive terminal of differentialamplifier 2906, and R_(FB) can represent a feedback resistor connectingoutput voltage V_(OUT) to a negative terminal of differential amplifier2906, in some examples.

FIG. 30 illustrates an exemplary voltage bias for a display-noise shieldof a touch screen stack-up according to examples of the disclosure. Insome examples, connection point C, representing a connection to theglobal mesh of display-noise shield 2210B, is grounded. Groundingdisplay-noise shield 2210B can mitigate noise, in some examples.Alternatively, display-noise shield 2210B can be biased to any fixed,non-zero voltage, in some examples (e.g., also to mitigate noise). Insome examples, display-noise shield 2210B is only biased to a ground, orother fixed voltage during touch sensing operations of touch sensor2216. In some examples (not illustrated by FIG. 30 ), display-noiseshield 2210B can be provided stimulation signals during touch sensingoperations that correspond to, or are based on stimulation signals 216of FIG. 2 , provided to drive lines 222 through drive interface 224.

FIG. 31 illustrates an example process 3100 for operating a touch screenstack-up with a touch sensor and a display-noise sensor between thetouch sensor and display pixels according to examples of the disclosure.In some examples, process 3100 describes operations for operating atouch screen stack-up with a touch sensor and a display-noise shieldbetween the touch sensor and the display pixels, as well. In someexamples, process 3100 can describe operations for operating readoutcircuit 2900 of FIG. 29 , whether the positive input 2904 is connectedto a display-noise sensor electrode (e.g., inputs B1/B2) or connected toa display-noise shield electrode (e.g., input C).

Process 3100 begins with readout circuitry (e.g., 2900 of FIG. 29 )sampling signals from a touch sensor 2216 at a particular location(e.g., row and/or column), at 3102. As an example, 3102 can describesampling signals from touch sensor 2216, particularly sampling aparticular location of the touch sensor where a touch event can bedetected (e.g., by touch controller 206). In such an example, a touchevent can be detected at a particular row (e.g., row two) and aparticular column (e.g., column three) of a display, and can correspondto a user interacting or selecting a user interface element displayed bydisplay components 2204 at the particular row and the particular column.Signals read out via terminals A1/A2 of FIG. 27 can be sampled and/orread out at negative input 2902 of readout circuit 2900 of FIG. 29 , at3102 of process 3100.

Process 3100 continues by the readout circuitry sampling signals fromdisplay-noise sensor at location corresponding to the particularlocation, at 3104. As an example, 3104 can describe sampling signalsfrom display-noise sensor 2210A at the same particular location that thetouch event was detected on the touch sensor. In such an example,display-noise sensor 2210A can be sampled at the particular row (e.g.,row two) and the particular column (e.g., column three) corresponding tothe location within display-noise sensor 2210A underneath the locationof the detected touch event on touch sensor 2216. Signals read out viaterminal B1/B2 of FIG. 27 can be sampled and/or read out at positiveinput 2904 of readout circuit 2900 of FIG. 29 , at 3104 of process 3100.In some examples, signals read out via terminal C of FIG. 28 can besampled and/or read out at positive input 2904 of readout circuit 2900of FIG. 29 , at 3104 of process 3100. In some examples, signals read outat positive input 2904 of readout circuit correspond to electrical noisesignals based on display components 2204, or changes in output values ofdisplay components 2204.

Process 3100 concludes by the readout circuitry generatingnoise-adjusted touch readout signals, by subtracting display-noisesensor signals from touch sensor panel signals, at 3106. As an example,3106 can describe differential amplifier 2906 generating an outputvoltage V_(OUT) corresponding to a difference of a signal at thepositive input 2904 and a signal at the negative input 2902. As anexample, V_(OUT) can be proportional to the signal at the positive input2904 minus (or, subtracted by) the signal at the negative input 2902,which is in turn proportional to the signal at the negative input 2902minus (or, subtracted by) the signal at the positive input 2904. Bydetermining the signal at the negative input 2902 minus the signal atthe positive input 2904, a noise-corrected touch readout signal can begenerated, at least because the signal at positive input 2904 read outfrom display-noise sensor 2210A can correspond to an electrical noisecontribution at the particular location (e.g., where a touch event wasdetected).

FIG. 32 illustrates an example process 3200 for forming a touch screenstack-up with a display-noise shield/sensor formed on a first printedlayer and a touch sensor formed on a second printed layer according toexamples of the disclosure. In some examples, process 3200 describesoperations for manufacturing first encapsulation layer 2208,display-noise shield/sensor 2210, second encapsulation layer 2212, andtouch sensor 2216 of stack-up 2200 of FIG. 22 , using an on-cellmanufacturing process. In some examples, on-cell manufacturing describedin the process 3200 can be alternatively descried as manufacturing firstencapsulation layer 2208, display-noise shield/sensor 2210, secondencapsulation layer 2212, and touch sensor 2216 in situ (e.g., in thesame place), as display components 2204. As described above inconnection with FIG. 22 , on-cell manufacturing processes can provideadvantages over alternative techniques of using discrete, andsemi-discrete components to form display-noise shield/sensor 2210 and/ortouch sensor 2216. In some examples, these advantages include theelimination of alignment and lamination steps associated with aligningthe (semi-)discrete component associated with a display-noiseshield/sensor to the already-manufactured layers 2202-2208 and using alaminate or adhesive to affix the component associated with thedisplay-noise shield/sensor to the already-manufactured layers2202-2208. These advantages of manufacturing display-noise shield/sensorusing an on-cell process contribute to lower yield losses of the overallstack-up 2200, relative to alternative processes.

Process 3200 begins by printing a first encapsulation layer (e.g., layer2208) over display components (e.g., display components 2204), at 3202.As mentioned above in connection with stack-up 2200 of FIG. 22 , firstencapsulation layer 2208 can be formed on top of passivation layer 2206,which covers an entirety of the light-emitting display pixels/elementsof display components 2204, and which sometimes covers portions of thelayer for display components 2204 where no light-emitting displaypixels/elements are formed. In some examples, printing firstencapsulation layer 2208 involves selective deposition (e.g., by ink-jetprinting methods) of the encapsulation layer material only over portionsof passivation layer 2206 formed over light-emitting displaypixels/elements of display components 2204. In such examples, firstencapsulation layer 2208 can be an optically transparent material thatcan be suitably deposited using selective deposition techniques (e.g.,an ink-jet printing process).

Process 3200 continues by forming display-noise shield/sensor overprinted first encapsulation layer, at 3204. As described above inconnection with FIG. 22 , display-noise shield/sensor 2210 can either bea shield, or a sensor, in some examples. Forming a display-noise shieldcan require forming a metal layer over the first encapsulation printedat 3202, in some examples (e.g., metal layer 2402 of FIG. 24 ). Forminga display-noise sensor can require forming multiple metal layersseparated by an interlayer dielectric layer between them, in someexamples (e.g., metal layers 2302 and 2306 separated by interlayerdielectric layer 2304 of FIG. 23 ).

Process 3200 continues by printing a second encapsulation layer over thedisplay-noise shield/sensor, at 3206. As described above in connectionwith FIG. 22 , second encapsulation layer 2212 can be selectively orblanket deposited over display-noise shield/sensor 2210. In someexamples, second encapsulation layer 2212 can be deposited over anentirety of display-noise shield/sensor 2210 (e.g., blanket deposition),or over only a portion of display-noise shield/sensor 2210 (e.g.,selective deposition). As an example, using blanket deposition, secondencapsulation layer 2212 can be deposited over an entirety ofdisplay-noise shield/sensor 2210 (e.g., blanket deposition), such thatthe surface of the second encapsulation layer is substantially flat(e.g., points on the surface of second encapsulation layer 2212 are allwithin a 5% range of a target level height for the second encapsulationlayer within stack-up 2200). As another example, using selectivedeposition, second encapsulation layer 2212 can be deposited over only aportion of display-noise shield/sensor 2210 such that the surface of thesecond encapsulation is uneven (e.g., at a height in deposition regions,and at a different height in non-deposition regions).

Process 3200 can conclude by forming a touch sensor over the printedsecond encapsulation layer, at 3208. As detailed in the description oftouch sensor 2216 in connection with FIG. 22 , a thick dielectric layer2214 can be formed over the second encapsulation layer 2212, to improveisolation of touch sensor 2216 from display-noise shield/sensor 2210(e.g., by reducing stray/parasitic capacitances between the two). Insome examples, touch sensor 2216 can be formed over the thick dielectriclayer 2214. In other examples, touch sensor 2216 can be formed directlyover second encapsulation layer 2212. Touch sensor 2216 of FIG. 22 ,when formed over the printed second encapsulation layer 2212 in this way(and/or over dielectric layer 2214 for additional isolation), has layersillustrated by FIG. 25 .

At 3208, a first metal layer (e.g., layer 2502 of FIG. 25 ) can beformed over the second encapsulation layer, followed by an interlayerdielectric layer (e.g., layer 2504 of FIG. 25 ), and a second metallayer (e.g., layer 2506 of FIG. 25 ). In some examples, the first andsecond metal layers can be used to form row touch electrodes and columntouch electrodes of a touch sensor. In such examples, the interlayerdielectric layer between the two metal layers can be patterned withvias, to allow interconnection between at least one portion of one metallayer with at least one portion of the other metal layer. As an example,row touch electrodes can be formed in the first metal layer, and columntouch electrodes can be formed in the second metal layer. As anotherexample, both row touch electrodes and column touch electrodes can beformed in the first metal layer, and the second metal layer can be usedto form conductive bridges to connect any discontinuous touch electrodesin the first metal layer.

FIG. 33 illustrates a portion of an example touch sensor panel accordingto examples of the disclosure. The portion of the touch sensor panel3300 (e.g., corresponding to touch sensor panel 700, 1100, 1300, etc.)includes a two-by-two array of touch nodes including four columnelectrodes 3304A-3304D (H-shaped electrodes) and four row electrodeslabeled 3302A-3302D. Some row routing traces 3306A-3306D and columnrouting traces 3308A-3308D are also shown. The row electrodes3302A-3302D can be routed to the sensing circuitry (e.g., single-endedamplifiers used for single-ended or differential measurements ordifferential amplifiers) using routing traces 3306A-3306D. The columnelectrodes 3304A-3304D can be routed to drive circuitry using routingtraces 3308A-3308D. The row and column routing traces can additionallyor alternatively connect to other portions of the row and columnelectrodes for other portions of the touch sensor panel outside thetwo-by-two array. The four row electrodes can be coupled to four inputsof the sensing circuitry, referenced with labels Rx0+, Rx0−, Rx1+, andRx1− (e.g., which may be used for two differential measurements). Thefour column electrodes can be coupled to four outputs of the drivecircuitry, referenced with labels Tx0+, Tx0−, Tx1+, and Tx1−.

As described herein, common mode noise from the display can be rejectedusing differential sensing (e.g., display-to-touch noise is common mode)and differential driving can reduce local imbalance on displayelectrodes from touch electrodes (e.g., the net touch drive signal isapproximately zero, thereby reducing touch-to-display noise). However,the noise reduction benefits of differential drive and sense techniquesapply to the two-by-two array of touch nodes (e.g., across the pitch oftwo touch nodes), whereas each touch node primarily corresponds to asingle-ended measurement touch signal of a respective row and column.For example, a first touch node (touch node A, upper left corner)measures the dominant mutual capacitance between column electrode 3304Aand row electrode 3302A, a second touch node (touch node B, upper rightcorner) measures the dominant mutual capacitance between columnelectrode 3304B and row electrode 3302B, a third touch node (touch nodeC, lower left corner) measures the dominant mutual capacitance betweencolumn electrode 3304C and row electrode 3302C, and a fourth touch node(touch node D, lower right corner) measures the dominant mutualcapacitance between column electrode 3304D and row electrode 3302D. Thenon-dominant (minor) mutual capacitances, however, can degrade thedifferential touch signal for each of the touch nodes.

In some examples, a touch electrode architecture for differential drivewithout differential sense can be implemented. Differential drive canstill reduce the touch-to-display noise (without differential sensing toreduce display-to-touch noise). The touch electrode architecture fordifferential drive can simplify the touch electrode architecture designbecause fewer routing traces and fewer bridges are required comparedwith some of the differential drive and differential sense touchelectrode architectures described herein (e.g., touch electrodearchitecture of FIG. 33 ).

FIG. 34 illustrates a portion of an example touch sensor panelconfigured for differential drive according to examples of thedisclosure. The portion of the touch sensor panel 3400 includes atwo-by-two array of touch nodes including four column electrodes3404A-3404D and two row electrodes labeled 3402A-3402B. The row touchelectrodes can be formed from a two-dimensional array of touch electrodesegments, which are horizontally interconnected using bridges 3410, andwhich can be vertically interconnected in a border region (e.g., outsideof the touch sensor panel area) and/or by additional bridges (notshown). As shown, each of the touch electrode segments for a rowelectrode is rectangular, but other shapes are possible. Six touchelectrode segments and four bridges are shown for each row electrode(e.g., two groups of three touch electrode segments and two bridges) forthe two-by-two array of touch nodes, but it is understood that differentnumbers of touch electrode segments and bridges can be used. Althoughnot shown, the row electrodes can be routed to sensing circuitry at theleft or right edges of the touch sensor panel (or optionally verticallyas described with reference to FIGS. 7A-14C). Additionally, as shown inFIG. 34 , the row electrodes are nearly entirely continuous across thetouch sensor panel (but for the bridges over column routing traces andrelatively small portions of column electrodes), which improves theconsistency of touch signal sensing when an object moves horizontallyacross the touch sensor panel (e.g., relative to the interleaved rowelectrodes of FIG. 33 ).

Each column electrode includes a plurality of touch electrode segmentsthat are connected by bridges 3412 and/or column routing traces3408A-3408D. As shown, each of the touch electrode segments for a columnelectrode are E-shaped (e.g., union of five rectangles, three of whichare parallel and the other two of which are orthogonal to andinterconnect the three), but other shapes are possible. A pair of theE-shaped touch electrode segments of a first column electrode for afirst touch node in a column are connected to a first column routingsegment and by a first three-way bridge 3412 (or by a three-way routingtrace in the same layer as the touch electrode segments). A pair of theE-shaped touch electrode segments of a second column electrode for asecond touch node in a column are connected to a first column routingsegment and by a second three-way bridge 3412 (or by a three-way routingtrace in the same layer as the touch electrodes segments). The firstcolumn routing trace 3408A for the first column electrode can bisect thepair of E-shaped column electrode segments of a second column electrodeinterleaved with the first column electrode. Similarly, the secondcolumn routing trace for the second column electrode can bisect a pairof E-shaped column electrode segments of the first column electrodeinterleaved with the second column electrode. It is understood that atthe transition from column routing trace 3408A to column routing trace3408B that one of the column routing traces can couple to correspondingcolumn touch electrode segments in the same layer as the column touchelectrode segments (e.g., using a three-way routing trace) and the otherof the column routing traces can couple to corresponding column touchelectrode segments using a three-way bridge 3412. In some examples,however, as illustrated, connections between each column routing traceand corresponding touch electrode segments can each be made usingbridges (but that this increases the number of bridges and require someadjustment to avoid the bridges intersecting one another). This patterndescribed for two touch nodes in one column can be repeated for thesecond column shown in FIG. 34 (and extended to a larger portion of thetouch sensor panel beyond the two-by-two array).

As shown, the pairs of E-shaped touch electrode segments are connectedby three-way bridge 3412 from each E-shaped touch electrode segment to acolumn routing trace. Although three-way bridges 3412 are illustrated toprovide a three-way connection between a column routing trace and a pairof E-shaped touch electrode segments, it is understood that differentbridge connections are possible. For example, a pair of bridges can beused instead of a three-way bridge or the pair of E-shaped touchelectrode segments can be connected by one or more horizontal bridgesand one or more additional bridges can connect from one or more of thepair of E-shaped touch electrode segments to the corresponding columnrouting trace.

As shown, the E-shaped electrodes can include a center bar that isthicker than the upper and lower bars. The dimensions of the E-shapedelectrodes can be optimized to improve total touch signal measured atthe touch nodes.

Each touch node includes a differential pair of column electrodes andsingle-ended row electrodes. For example, a first touch node (touch nodeA, upper left corner) includes a portion of row electrode 3402A (e.g.,corresponding to a single-ended input for touch sensing), a portion ofcolumn electrode 3404A, and a portion of column routing trace 3408C(e.g., corresponding to differential, complimentary outputs of touchdriving). Similarly, a second touch node (touch node B, upper rightcorner) includes a portion of row electrode 3402A (e.g., correspondingto a single-ended input for touch sensing), a portion of columnelectrode 3404B, and a portion of column routing trace 3408F (e.g.,corresponding to differential, complimentary outputs of touch driving);a third touch node (touch node C, lower left corner) includes a portionof row electrode 3402B (e.g., corresponding to a single-ended input fortouch sensing), a portion of column electrode 3404C, and a portion ofcolumn routing trace 3408A (e.g., corresponding to differential,complimentary outputs of touch driving); and a fourth touch node (touchnode D, lower right corner) includes a portion of row electrode 3402B(e.g., corresponding to a single-ended input for touch sensing), aportion of column electrode 3404D, and a portion of column routing trace3408B (e.g., corresponding to differential, complimentary outputs oftouch driving). The differential cancelation of the drive signals occursacross the two touch nodes in each column.

The touch electrode architecture of FIG. 34 can provide a simplifieddesign in the form of fewer traces and bridges. For example, the touchelectrode architecture of FIG. 34 includes four column electrodes, butonly two row electrodes, thereby reducing the number of routing tracesfrom eight to six compared with the touch electrode architecture of FIG.33 . The simplified architecture can also reduce the number of bridgesrequired.

Although FIG. 34 provides some simplifications to the touch electrodearchitecture (e.g., fewer routing traces and bridges), it may bedesirable to have an improved cancelation resolution (e.g., cancelationthat occurs in a smaller area for better cancelation performance). Insome examples, a touch electrode architecture for differential drive anddifferential sense can be implemented in which the row electrodes areinterleaved and the column electrodes are not, or in which the columnelectrodes are interleaved and the row electrodes are not. Although oneset of touch electrodes are not interleaved, the touch signal processingalgorithm can be adjusted to achieve a pseudodifferential result (e.g.,mimicking the result from physically interleaving).

FIGS. 35A-35B illustrate example touch electrode architectures accordingto examples of the disclosure. The touch electrode architectures ofFIGS. 35A-35B include the same number of electrodes (and correspondingrouting traces to drive and sensing circuitry) as the touch electrodearchitecture of FIG. 33 . However, unlike the touch electrodearchitecture of FIG. 33 , the touch electrode architectures of FIGS.35A-35B reduce the distance over which the differential effects areachieved. For example, assuming the same dimensions for the two-by-twoarray of touch nodes in FIGS. 33 and 35A or 35B, the differentialcancelation occurs over half the distance (e.g., over half the touchelectrode pitch) for the touch electrode architectures of FIGS. 35A-35Bcompared with the touch electrode architecture of FIG. 33 .

The portion of the touch sensor panel 3500 illustrated in FIG. 35Aincludes a two-by-two array of touch nodes including four columnelectrodes 3504A-3504D and four row electrodes labeled 3502A-3502D. Eachrow electrode includes a plurality of touch electrode segments that areconnected by bridges 3510 over column routing traces. As shown, each ofthe touch electrode segments for a row electrode is rectangular, butother shapes are possible. Three touch electrode segments and twobridges are shown for each row electrode in the two-by-two touch nodearray, but it is understood that different numbers of touch electrodesegments and bridges can be used. Although not shown, the row electrodescan be routed to sensing circuitry at the left or right edges of thetouch sensor panel (or optionally vertically as described with referenceto FIGS. 7A-14C). Additionally, as shown in FIG. 35A, the row electrodesare nearly entirely continuous across the touch sensor panel (but forthe bridges over column routing traces and relatively small portions ofcolumn electrodes), which improves the consistency of touch signalsensing when an object moves horizontally across the touch sensor panel(e.g., relative to the interleaved row electrodes of FIG. 33 ).

Each column electrode includes a plurality of touch electrode segmentsthat are connected by three-way bridges 3512 and column routing traces3508A-3508D. As shown, each of the touch electrode segments for a columnelectrode are U-shaped (e.g., union of three rectangles, two of whichare parallel, and the third of which is orthogonal to and interconnectsthe two), but other shapes are possible. A pair of the U-shaped touchelectrode segments of a first column electrode for a first touch node ina column and a pair of U-shaped touch electrode segments of the firstcolumn electrode for a second touch node in the column are connected bya first column routing segment and by a first three-way bridge 3512 (ora three-way routing connection in the same layer as the touch electrodesegments). The first column routing trace for the first column electrodecan bisect a pair of U-shaped column electrode segments of a secondcolumn electrode interleaved with the first column electrode. Similarly,a pair of the U-shaped touch electrode segments of a second columnelectrode for the first touch node in the column and a pair of U-shapedtouch electrode segments of the second column electrode for a secondtouch node in the column are connected by second column routing segmentand by a second three-way bridge 3512 (or a three-way routing connectionin the same layer as the touch electrode segments). The second columnrouting trace for the second column electrode can bisect a pair ofU-shaped column electrode segments of the first column electrodeinterleaved with the second column electrode. This pattern can berepeated for the second column shown in FIG. 35A (and extended to alarger portion of the touch sensor panel beyond the two-by-two array).Each pair of U-shaped touch electrode segments can be view as forming asplit H-shape (e.g., the U-shaped touch electrode segments are mirroredover the bisecting column routing trace for the interleaved columnelectrode).

As shown, the pairs of U-shaped touch electrode segments are connectedby three-way bridges 3512 (or three-way routing connections in the samelayer as the touch electrode segments) from each U-shaped touchelectrode segment to a column routing trace. Although a pair ofthree-way bridges 3512 are illustrated to provide a three-way connectionbetween a column routing trace and a pair of U-shaped touch electrodesegments, it is understood that different bridge connections arepossible. For example, a pair of bridges can be used instead of athree-way bridge or the pair of U-shaped touch electrode segments can beconnected by one or more horizontal bridges and one or more bridges canconnect from one or more of the pair of U-shaped touch electrodesegments to the corresponding column routing trace. Four touch electrodesegments and four bridges are shown for each column electrode in FIG.35A, but it is understood that different numbers of touch electrodesegments and bridges can be used.

Each touch node includes a differential pair of row electrodes and adifferential pair of column electrodes. For example, a first touch node(touch node A, upper left corner) includes a portion of row electrode3502A and a portion of a second row electrode 3502B (e.g., correspondingto differential inputs for touch sensing), and a portion of columnelectrode 3504A and a portion of column electrode 3504B (e.g.,corresponding to differential, complimentary outputs of touch driving).Thus, the differential cancelation occurs on a per touch node basisrather than across two touch nodes. Similarly, a second touch node(touch node B, upper right corner) includes a portion of row electrode3502A and a portion of a second row electrode 3502B (e.g., correspondingto differential inputs for touch sensing), and a portion of columnelectrode 3504C and a portion of column electrode 3504D (e.g.,corresponding to differential, complimentary outputs of touch driving);a third touch node (touch node C, lower left corner) includes a portionof row electrode 3502C and a portion of a second row electrode 3502D(e.g., corresponding to differential inputs for touch sensing), and aportion of column electrode 3504A and a portion of column electrode3504B (e.g., corresponding to differential, complimentary outputs oftouch driving); and a fourth touch node (touch node D, lower rightcorner) includes a portion of row electrode 3502C and a portion of asecond row electrode 3502D (e.g., corresponding to differential inputsfor touch sensing), and a portion of column electrode 3504C and aportion of column electrode 3504D (e.g., corresponding to differential,complimentary outputs of touch driving). Thus, the differentialcancelation occurs on a per touch node basis for each touch node in thetwo-by-two array of touch nodes.

The touch signal level can be improved and parasitic losses reduced fortouch electrode architecture of FIG. 35A relative to the touch electrodearchitecture of FIG. 33 . For example, unlike the touch electrodearchitecture of FIG. 33 , two dominant and complimentary mutualcapacitance are represented at each touch node in FIG. 35A. For example,a first touch node (touch node A, upper left corner) measures thedominant mutual capacitance between column electrode 3504A (Tx0+) androw electrode 3502A (Rx0+) and the complimentary dominant mutualcapacitance between column electrode 3504B (Tx0−) and row electrode3502B (Rx0−); a second touch node (touch node B, upper right corner)measures the dominant mutual capacitance between column electrode 3504C(Tx1+) and row electrode 3502A (Rx0+) and the complimentary dominantmutual capacitance between column electrode 3504D (Tx1−) and rowelectrode 3502B (Rx0−); a third touch node (touch node C, lower leftcorner) measures the dominant mutual capacitance between columnelectrode 3504A (Tx0+) and row electrode 3502C (Rx1+) and thecomplimentary dominant mutual capacitance between column electrode 3504B(Tx0−) and row electrode 3502D (Rx1−); and a fourth touch node (touchnode D, lower right corner) measures the dominant mutual capacitancebetween column electrode 3504C (Tx1+) and row electrode 3502C (Rx1+) andthe complimentary dominant mutual capacitance between column electrode3504D (Tx1−) and row electrode 3502D (Rx1−). The two dominant mutualcapacitances in each node sum due to the fact that they are in-phasewith one another.

Additionally, the non-dominant (minor) parasitic capacitance can bereduced in touch electrode architecture of FIG. 35A compared with thetouch electrode architecture of FIG. 33 . For example, for the firsttouch node (touch node A), there is still some parasitic capacitance dueto the mutual capacitance between column routing trace 3508B (Tx0−) androw electrode 3502A (Rx0+) (and there is still some parasiticcapacitance due to the mutual capacitance between column routing trace3508A (Tx0+) and row electrode 3502B (Rx0−)), but separation isincreased between column electrode 3504B (Tx0−) and row electrode 3502A(Rx0+), and between column electrode 3504A (Tx0+) and row electrode3502B (Rx0−), and the row routing is reduced compared with the touchelectrode architecture of FIG. 33 (e.g., the length and proximity ofcolumn routing trace 3308C to row electrode 3302A is eliminated),thereby reducing the parasitic signal loss due to the mutual capacitancetherebetween.

In some examples, the touch electrode architecture of FIG. 35A can beused for single-ended sensing. For example, switching circuitry (notshown) can be implemented to enable either a pair of row electrodes tobe differentially sensed (e.g., row electrode 3502A is coupled to onedifferential input and row electrode 3502B is coupled to a seconddifferential input of the sensing circuitry), or to be sensed in asingle-ended fashion (e.g., row electrodes 3502A and 3502B are coupledtogether and to one single-ended input of the sensing circuitry). Insome examples, switching circuitry can enable single-ended sensing at asmaller pitch (e.g., row electrode 3502A is coupled to one single-endedinput and row electrode 3502B is coupled to another single-ended inputof the sensing circuitry). As described herein, the touch electrodearchitecture of FIG. 33 can also be used for single-ended sensing, butdue to the interleaving of the row electrodes, the measurements may beoffset between adjacent rows.

FIG. 35B illustrates a variation on FIG. 35A, but with the rowelectrodes interleaved and the column electrodes not interleaved (e.g.,pseudo-interleaved due to modifications of the touch sensing algorithm).For example, the portion of the touch sensor panel 3520 illustrated inFIG. 35B includes a two-by-two array of touch nodes including fourcolumn electrodes 3524A-3524D and four row electrodes labeled3522A-3522D. Each column electrode includes a plurality of touchelectrode segments that are connected by bridges 3530 over row routingtraces. As shown, each of the touch electrode segments for a columnelectrode is rectangular, but other shapes are possible. Three touchelectrode segments and two bridges are shown for each column electrodein the two-by-two array of touch nodes, but it is understood thatdifferent numbers of touch electrode segments and bridges can be used.Although not shown, the column electrodes can be routed to drivecircuitry at the top or bottom edges of the touch sensor panel (oroptionally horizontally in a similar manner as described herein for rowelectrodes used for sensing).

Each row electrode includes a plurality of touch electrode segments thatare connected by three-way bridges 3532 and row routing traces3526A-3526D. As shown, each of the touch electrode segments for a rowelectrode are U-shaped (e.g., union of three rectangles, two of whichare parallel and the third of which is orthogonal to and interconnectsthe two), but other shapes are possible. A pair of the U-shaped touchelectrode segments of a row electrode for a first touch node in a rowand a pair of U-shaped touch electrode segments of the first rowelectrode for a second touch node in the row are connected by a firstrow routing segment and by a first three-way bridge 3532 (or a three-wayrouting connection in the same layer as the touch electrode segments).The first row routing trace for the first row electrode can bisect apair of U-shaped row electrode segments of a second row electrodeinterleaved with the first row electrode. Similarly, a pair of theU-shaped touch electrode segments of a second row electrode for thefirst touch node in the row and a pair of U-shaped touch electrodesegments of the second row electrode for a second touch node in the roware connected by second row routing segment and by a second three-waybridge 3532 (or a three-way routing connection in the same layer as thetouch electrode segments). The second row routing trace for the secondrow electrode can bisect a pair of U-shaped row electrode segments ofthe first row electrode interleaved with the second row electrode. Thispattern can be repeated for the second row of touch nodes shown in FIG.35B (and extended to a larger portion of the touch sensor panel beyondthe two-by-two array). Each pair of U-shaped touch electrode segmentscan be view as forming a split H-shape (e.g., the U-shaped touchelectrode segments are mirrored over the bisecting row routing trace forthe interleaved row electrode).

As shown, the pairs of U-shaped touch electrode segments are connectedby three-way bridges 3532 (or a three-way routing connection in the samelayer as the touch electrode segments) from each touch electrode segmentto a row routing trace. Although a pair of three-way bridges 3532 areillustrated to provide a three-way connection between a row routingtrace and a pair of U-shaped touch electrode segments, it is understoodthat different bridge connections are possible. For example, a pair ofbridges can be used instead of a three-way bridge or the pair ofU-shaped touch electrode segments can be connected by vertical bridgesand one or more bridges can connect from one or more of the pair ofU-shaped touch electrode segments to the corresponding row routingtrace. Four touch electrode segments and four bridges are shown for eachrow electrode in FIG. 35B, but it is understood that different numbersof touch electrode segments and bridges can be used.

Each touch node includes a differential pair of row electrodes and adifferential pair of column electrodes. For example, a first touch node(touch node A, upper left corner) includes a portion of row electrode3522A and a portion of a second row electrode 3522B (e.g., correspondingto differential inputs for touch sensing), and a portion of columnelectrode 3524A and a portion of column electrode 3524B (e.g.,corresponding to differential, complimentary outputs of touch driving).Thus, the differential cancelation occurs on a per touch node basisrather than across two touch nodes. Similarly, a second touch node(touch node B, upper right corner) includes a portion of row electrode3522A and a portion of a second row electrode 3522B (e.g., correspondingto differential inputs for touch sensing), and a portion of columnelectrode 3524C and a portion of column electrode 3524D (e.g.,corresponding to differential, complimentary outputs of touch driving);a third touch node (touch node C, lower left corner) includes a portionof row electrode 3522C and a portion of a second row electrode 3522D(e.g., corresponding to differential inputs for touch sensing), and aportion of column electrode 3524A and a portion of column electrode3524B (e.g., corresponding to differential, complimentary outputs oftouch driving); and a fourth touch node (touch node D, lower rightcorner) includes a portion of row electrode 3522C and a portion of asecond row electrode 3522D (e.g., corresponding to differential inputsfor touch sensing), and a portion of column electrode 3524C and aportion of column electrode 3524D (e.g., corresponding to differential,complimentary outputs of touch driving). Thus, the differentialcancelation occurs on a per touch node basis for each touch node in thetwo-by-two array of touch nodes.

The touch signal level can be improved and parasitic losses reduced fortouch electrode architecture of FIG. 35B relative to the touch electrodearchitecture of FIG. 33 . For example, unlike the touch electrodearchitecture of FIG. 33 , two dominant and complimentary mutualcapacitance are represented at each touch node in FIG. 35B. For example,a first touch node (touch node A, upper left corner) measures thedominant mutual capacitance between column electrode 3524A (Tx0+) androw electrode 3522A (Rx0+), and the complimentary dominant mutualcapacitance between column electrode 3524B (Tx0−) and row electrode3522B (Rx0−); a second touch node (touch node B, upper right corner)measures the dominant mutual capacitance between column electrode 3524C(Tx1+) and row electrode 3522A (Rx0+), and the complimentary dominantmutual capacitance between column electrode 3524D (Tx1−) and rowelectrode 3522B (Rx0−); a third touch node (touch node C, lower leftcorner) measures the dominant mutual capacitance between columnelectrode 3524A (Tx0+) and row electrode 3522C (Rx1+), and thecomplimentary dominant mutual capacitance between column electrode 3524B(Tx0−) and row electrode 3522D (Rx1−); and a fourth touch node (touchnode D, lower right corner) measures the dominant mutual capacitancebetween column electrode 3524C (Tx1+) and row electrode 3522C (Rx1+),and the complimentary dominant mutual capacitance between columnelectrode 3524D (Tx1−) and row electrode 3522D (Rx1−). The two dominantmutual capacitances in each node sum due to the fact that they arein-phase with one another.

Additionally, the non-dominant (minor) parasitic capacitance can bereduced due to increased separation column electrode 3524B (Tx0−) androw electrode 3522A (Rx0+), and between column electrode 3524A (Tx0+)and row electrode 3522B (Rx0−), and due to the reduced column routing.

FIG. 36 illustrates an example touch electrode architecture that isfully differential within a touch node according to examples of thedisclosure. In the touch electrode architecture of FIG. 36 , both therow and the column electrodes can be differentially interleaved within atouch node. The portion of the touch sensor panel 3600 illustrated inFIG. 36 corresponds to a single touch node and could be applied as amodification of each of the touch nodes in the touch electrodearchitectures of FIG. 35A or FIG. 35B (or across a larger touch sensorpanel). The touch electrodes illustrated includes two column electrodes3604A-3604B and two row electrodes 3602A-3602B (extended to four columnelectrodes and four row electrodes for a two-by-two array of touchnodes). Each row electrode includes a plurality of touch electrodesegments that are connected by bridges 3606A-3606B. As shown, each ofthe touch electrode segments for a row electrode is rectangular (with arectangular routing extension to reduce the bridge length), but othershapes are possible. Two touch electrode segments and one bridge areshown for each row electrode, but it is understood that differentnumbers of touch electrode segments and bridges can be used.

Each column electrode includes a plurality of touch electrode segmentsthat are connected by a bridge (e.g., bridges 3608A-3608B) or a routingtraces. As shown, each of the touch electrode segments for a columnelectrode are complimentary to the shape of the touch electrode segmentsfor a row electrode. The shape of the touch electrode segments for acolumn electrode is approximately U-shaped (apart from the modificationto allow for the routing extension for the row touch electrode segment),but other shapes are possible. Two touch electrode segments and onebridge (or a routing trace) are shown for each column electrode, but itis understood that different numbers of touch electrode segments andbridges can be used.

As shown, the touch node includes a differential pair of row electrodesand a differential pair of column electrodes. For example, the touchnode of FIG. 36 includes a portion of a first row electrode 3602A and aportion of a second row electrode 3602B (e.g., corresponding todifferential inputs for touch sensing), and a portion of columnelectrode 3604A and a portion of column electrode 3604B (e.g.,corresponding to differential, complimentary outputs of touch driving).Thus, the differential cancelation occurs on a per touch node basis. Theimproved touch signal from two (or four if each quadrant of the touchnode is viewed separately) dominant capacitances can be applied in asimilar fashion to other touch nodes.

The touch signal level can be improved and parasitic losses reduced fortouch electrode architecture of FIG. 36 relative to the touch electrodearchitecture of FIG. 33 . For example, unlike the touch electrodearchitecture of FIG. 33 , two (or four if each quadrant of the touchnode is viewed separately) dominant and complimentary mutual capacitanceare represented at the touch node in FIG. 36 . For example, the touchnode measures the dominant mutual capacitance between column electrode3604A (Tx0+) and row electrode 3602A (Rx0+), and the complimentarydominant mutual capacitance between column electrode 3604B (Tx0−) androw electrode 3602B (Rx0−). The two (or four) dominant mutualcapacitances in each node sum due to the fact that they are in phasewith one another.

Additionally, the non-dominant (minor) parasitic capacitance can bereduced. For example, there is still some parasitic capacitance due tothe mutual capacitance between column electrode 3604B (Tx0−) and rowelectrode 3602A (Rx0+), and between column electrode 3604A (Tx0+) androw electrode 3602B (Rx0−), but separation is mainly increased (outsideof the small row extension) and limited by the short routing, therebyreducing the parasitic signal loss due to the mutual capacitancetherebetween. The reduced parasitic loss from two non-dominantcapacitances can be applied in a similar fashion to other touch nodes.

Referring back to the discussion of FIG. 34 , in some examples, a touchelectrode architecture for differential drive without differential sensecan be implemented. Differential drive can still reduce thetouch-to-display noise (without differential sensing to reducedisplay-to-touch noise). Additionally, common mode noise can be reducedusing spatial separation and spatial filtering. The spatial separationbetween touch signal and common mode noise signal can be achieved usinga touch electrode architecture with reduced pitch for the transmitterand receiver electrodes.

FIG. 37 illustrates a portion of an example touch sensor panelconfigured for differential drive according to examples of thedisclosure. The portion of the touch sensor panel 3700 includes afour-by-four array of touch nodes including eight transmitter electrodesinterleaved in four rows of touch nodes and eight receiver electrodes infour columns of touch nodes. To simplify illustration, bridges are notshown in FIG. 37 , but it is understood that most of the touchelectrodes in FIG. 37 are implemented in a first metal mesh layer withbridges in a second metal mesh layer.

As shown in touch sensor panel 3700, the first row includes a first pairof interleaved transmitter electrodes labeled D0+ and D0− representingthe complimentary drive signal applied to this row during touch sensingoperation; the second row includes a second pair of interleavedtransmitter electrodes labeled D1+ and D1− representing thecomplimentary drive signal applied to this row during touch sensingoperation; the third row includes a third pair of interleavedtransmitter electrodes labeled D2+ and D2− representing thecomplimentary drive signal applied to this row during touch sensingoperation; and the fourth row includes a fourth pair of interleavedtransmitter electrodes labeled D3+ and D3− representing thecomplimentary drive signal applied to this row during touch sensingoperation. Additionally touch sensor panel 3700 shows the first columnincludes a first pair of non-interleaved receiver electrodes labeled S0_(A) and S0 _(B) representing two singled-ended sense lines for thiscolumn during touch sensing operation; the second column includes asecond pair of non-interleaved receiver electrodes labeled S1 _(A) andS1 _(B) representing two singled-ended sense lines for this columnduring touch sensing operation; the third column includes a third pairof non-interleaved receiver electrodes labeled S2 _(A) and S2 _(B)representing two singled-ended sense lines for this column during touchsensing operation; and the fourth column includes a fourth pair ofnon-interleaved receiver electrodes labeled S3 _(A) and S3 _(B)representing two singled-ended sense lines for this column during touchsensing operation.

FIG. 37 illustrates a touch node 3710 corresponding to a unit cell ofthe touch electrode architecture, which can be repeated for thefour-by-four array of touch nodes (or beyond for a larger touch sensorpanel). During touch sensing operation, the first pair of interleavedtransmitter electrodes labeled D0+ and D0− can be stimulated, andresultant mutual capacitance(s) can be measured by the correspondingfirst pair of receiver electrodes labeled S0 _(A) and S0 _(B). The touchsignal for touch node 3710 can be represented as a sum of the touchsignal measured from the pair of receiver electrodes.

FIG. 37 also indicates a data line orientation for touch sensor panel3700. As shown in FIG. 37 , the data line is oriented orthogonal to thereceiver electrodes (e.g., such that the receiver electrodes receive anaverage of the display data line noise) and parallel to the transmitterelectrodes. As described herein, the data lines of the display representa source of noise for the touch sensing system, also referred to hereinas “cathode noise.” FIG. 37 illustrates representative spatial shapes3720 of cathode noise along the direction of the touch transmitterelectrodes and representative spatial shapes 3740 of the cathode noisealong the direction (e.g., orthogonal) of the touch receiver electrodes.The spatial shapes of cathode noise can be similar in along thedirection of the touch transmitter electrodes (e.g., similar RCcharacteristics), with the amplitude of the shape generally scaling withgray levels of different display images (e.g., a nearly constant noisespatial spectrum). In contrast, the spatial shapes of cathode noise canbe varied and image dependent along the direction of the touch receiverelectrodes. Additionally, the spatial shapes of cathode noise along thedirection of the touch transmitter electrodes can be measured in acorrelated manner with the analog front ends (sensing circuitry) for thereceiver electrodes, whereas the spatial shapes of cathode noise alongthe direction of the touch receiver electrodes can be measured in atemporarily uncorrelated manner.

Accordingly, the touch electrode architecture can achieve spatial noiseremoval by encoding the stimulation of the transmitter electrodes alongthe direction of the correlated and shape consistent cathode noise alongthe direction of the interleaved transmitter electrodes. Additionally,as described herein with respect to FIGS. 38-39 , the spatial separationand spatial noise removal can be improved by reducing the pitch of thetouch electrodes.

FIG. 39 illustrates three plots of spatial touch signal and noiseaccording to examples of the disclosure. Plot 3900 show a spatial datacorresponding to different touches and to noise along an axis of a touchsensor panel (e.g., corresponding to touch sensor panel 3700 or 3800).The axis of the touch sensor panel is represented by an array 3902 ofreceiver electrodes with a receiver electrode pitch P_(RX). The barsabove the array 3902 of receiver electrodes represent the touch signaland/or noise signal at the corresponding receiver electrodes. As shown,a first profile 3904 corresponds to a first touching object (e.g., asmall finger) and a second profile 3906 corresponds to a second touchingobject (e.g., a larger finger or multiple small fingers). Profile 3908represents the cathode noise. The data represented in plot 3900 isspatial data, and as shown the profile of the cathode noise has aspatial shape corresponding to the spatial shapes 3720 of cathode noisealong the direction of the touch transmitter electrodes. As shown, theshape of the cathode noise is spatially wide relative to the spatialwidth of the first or second touching objects (e.g., extends across thepanel), and has a low frequency (e.g., relative to the noise along theorthogonal axis).

Plot 3920 shows a spatial spectrum corresponding to the spatial data inplot 3900. Profile 3922 represents the spatial spectral domaincorresponding to the cathode noise of profile 3908 in the spatial data.The relatively wide noise signal has a low-frequency and thereforeappears near the center of the spatial spectrum in the spatial spectraldomain (e.g., at low spatial frequencies, centered around zero). Incontrast, profile 3924 represents the spatial spectral domaincorresponding to profiles 3904 and/or 3906 of the touch signal(s) in thespatial data. The relatively narrow touch signals in the spatial dataappear wider in the spatial spectral domain compared with the noise.However, plot 3920 corresponds to a non-differential transmit electrodeconfiguration (e.g., without the interleaving and stimulation withcomplementary drive signals).

Plot 3940 shows a spatial spectrum corresponding to the spatial data inplot 3900, but when using a differential transmit electrodeconfiguration. In plot 3940, the cathode noise from the display is notcoded, and therefore the profile 3942 of the spectrum of the cathodenoise remains the same as profile 3922 in plot 3920. However, using thedifferential transmitter configuration to encode the spectrum for touchsignal causes an up-conversion of the touch signal in the spatialspectral domain that results in two half-lobes 3944A and 3944B. The twohalf-lobes 3944A and 3944B resulting from the up-conversion can, in someexamples, at least partially overlap. For example, plot 3940 illustratessome overlap between profiles 3942 and half-lobes 3944A or 3944B. Insome examples, with enough up-conversion through decreasing thetransmitter and/or receiver pitch the separation between the profiles inthe spatial spectral domain can be improved or eliminated. The spatiallyseparated signals can be filtered using a spatial high pass filter toremove the noise (and possibly some of the touch signal when someoverlap remains).

In some examples, a no-overlap condition between the cathode noise andthe touch signal spatial spectra can be expressed as Ts+Ns<1/P_(RX),where Ts represents the touch signal spatial spectrum width, Nsrepresents the noise signal spatial spectrum width, and P_(RX)represents the receiver electrode pitch.

In some examples, the coding can be viewed as causing the touch signalto have a sawtooth shape or other relatively-high frequency shape (e.g.,due to the coded differential stimulation) that is easier to resolvefrom the flatter, common mode shape of the cathode noise. In particular,as described herein, the flatter, common mode shape of the cathode noise(having relatively low-frequency, and correlated shape) for transmitterelectrodes parallel to the data lines.

FIG. 38 illustrates a portion of an example touch sensor panelconfigured for differential drive according to examples of thedisclosure. The portion of the touch sensor panel 3800 includes aone-by-four array of touch nodes including eight transmitter electrodes(labeled D0+, D0−, D1+, D1, D2+, D2−, D3+, and D3−) interleaved in fourrows of touch nodes and two receiver electrodes (labeled S0 _(A) and S0_(B)) in one columns of touch nodes. To simplify illustration, bridgesare not shown in FIG. 38 , but touch node 3810 (corresponding to theoverall dimensions of touch node 3710) is included for reference.Additionally, for ease of illustration, the dimensions of the portion oftouch sensor panel 3800 are exaggerated (e.g., width is exaggeratedrelative to length to show the details of the features), but it isunderstood that touch nodes 3810 and 3710 can have the same overalldimensions.

Unlike FIG. 37 , which includes two interleaved transmitter electrodeseach with one primary rectangular segment (e.g., primary rectangularsegment 3712A and 3712B for transmitter electrodes D0+ and D0− in touchnode 3710) and one interleaving transition between the transmitterelectrodes within a touch node, in FIG. 38 , the two interleavedtransmitter electrodes each with include multiple primary rectangularsegments (e.g., four primary rectangular segments 3812A and four primaryrectangular segments 3812B for transmitter electrodes D0+ and D0− intouch node 3810) and seven interleaving transition between thetransmitter electrodes within a touch node.

As described herein, encoding the touch signals to higher spatialfrequencies compared with cathode noise enables separation of the touchand noise spatial spectra for noise removal. The separation can beimproved by reducing the receiver electrode pitch. Comparing FIGS. 37and 38 , the receiver electrode pitch, P_(RX), can be reduced byapproximately a factor of four (e.g., with touch nodes 3710 and 3810having the same dimensions). It is understood that although FIG. 37illustrates one primary rectangular segment per transmitter electrodeand FIG. 38 illustrates four primary rectangular segments pertransmitter electrode, that different numbers of primary rectangularsegment per transmitter electrode are possible (e.g., two, three, five,etc.).

Although reducing the receiver electrode pitch can provide betterseparation, it is understood that there are tradeoffs. For example,comparing FIGS. 37 and 38 , two receiver electrodes of FIG. 37 arereplaced with eight narrower receiver electrodes of FIG. 38 . As aresult, the touch sensing circuitry potentially requires a four-foldmultiplication in number of receiver channels which increases the size,cost, and power consumption of the touch sensing circuitry (or requiresa reduced integration time if the channels are multiplexed betweenreceiver electrodes). In some examples, the above sensing circuitry (orintegration time) penalties can be mitigated by interconnecting (e.g.,grouping/ganging) the increased number of narrower receiver electrodes.For example, as shown in FIG. 38 , four receiver electrodes areinterconnected and can be connected to one single-ended sensing channelof the touch sensing circuitry and another four receiver electrodes areinterconnected and can be connected to another single-ended sensingchannel of the touch sensing circuitry. The interconnections avoid theneed for additional sensing circuitry and the touch node resolution ofthe touch sensor panel is unchanged between touch sensor panels 3700 and3800. In some examples, the interconnection between multiple receiverelectrodes occurs at the touch sensor panel boundary (e.g., in a borderregion) to reduce the number of in-panel jumper and/or vias. However, itis understood that in some examples, the interconnection canadditionally or alternatively be performed within the touch sensor panelarea.

The grouping of receiver electrodes may avoid the touch sensingcircuitry penalty, but reducing the receiver electrode can entail othertradeoffs. For example, narrower receiver electrodes can result inincreased resistance, which thereby reduces touch sensor panel bandwidth(although the impact on bandwidth may be somewhat mitigated by thereduced load of the narrower receiver electrodes). Additionally oralternatively, the narrower receiver electrodes and the correspondingreduction in the transmitter electrode pitch can reduce the reach ofmutual capacitance fringing fields. If the fringing fields are reducedtoo much, they may not be able to extend far enough beyond the touchsensor panel surface (e.g., a cover glass or other material) to be ableto interact with objects (e.g., fingers).

It is understood the spatial noise removal techniques described hereinwith respect to FIGS. 37-39 can be applied to other touch electrodearchitectures. For example, the pitch of the receiver electrodes and thecorresponding pitch of the interleaved transmitter electrodes can beapplied to the interleaved transmitter electrodes (e.g., columnelectrodes) and non-interleaved receiver electrodes (e.g., rowelectrodes) in the touch electrode architecture of FIGS. 34 and 35A.

Therefore, according to the above, some examples of the disclosure aredirected to a touch sensor panel. The touch sensor panel can comprise: aplurality of touch electrodes including a plurality of first electrodesand a plurality of second electrodes in a first layer, the plurality oftouch electrodes forming a two-axis array of touch nodes; a plurality offirst routing traces in a second layer, different from the first layer,the plurality of first routing traces coupled to the first electrodesusing a plurality of first electrical interconnections between the firstlayer and the second layer; and a plurality of second routing traces inthe second layer, the plurality of the second routing traces coupled tothe second electrodes using a plurality of second electricalinterconnections between the first layer and the second layer.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the plurality of first routing traces can berouted along a first axis of the two-axis array and can at leastpartially overlap the two-axis array of touch nodes. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the plurality of second traces can be routed along the firstaxis of the two-axis array and can at least partially overlap thetwo-axis array of touch nodes.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first electrodes can include columnelectrodes, the second electrodes can include row electrodes, and thetwo-axis array of touch nodes can include a row-column arrangement oftouch nodes. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the second layer cancomprises, for a first column of the row-column arrangement of touchnodes, a plurality of sets of one or more routing trace segments, theplurality of sets of one or more routing trace segments including afirst set of one or more routing trace segments, a second set of one ormore routing trace segments, a third set of one or more routing tracesegments, and a fourth set of one or more routing trace segments.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the second layer can comprise, for a firstcolumn of the row-column arrangement of touch nodes, a plurality of setsof one or more routing trace segments, the plurality of sets of one ormore routing trace segments including a first set of one or more routingtrace segments, a second set of one or more routing trace segments, athird set of one or more routing trace segments, a fourth set of one ormore routing trace segments, a fifth set of one or more routing tracesegments, and a sixth set of one or more routing trace segments.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first column can include a first columnelectrode and a second column electrode, the first set of one or morerouting trace segments can comprise a first routing trace of theplurality of first routing traces, the second set of one or more routingtrace segments can comprise a second routing trace of the plurality offirst routing traces are disposed in the first column, the first routingtrace of the plurality of first routing traces can be coupled to thefirst column electrode, and the second routing trace of the plurality offirst routing traces can be coupled to the second column electrode.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, a first routing trace of the plurality ofsecond routing traces, a second routing trace of the plurality of secondrouting traces, and a third routing trace of the plurality of secondrouting traces can be disposed in the first column. The first routingtrace of the plurality of second routing traces can comprise a firstportion of the first set of one or more routing trace segments, a firstportion of the second set of one or more routing trace segments, a firstportion of the third set of one or more routing trace segments, and afirst portion of the fourth set of one or more routing trace segments.The second routing trace of the plurality of second routing traces cancomprise a second portion of the first set of one or more routing tracesegments and a second portion of the second set of one or more routingtrace segments. The third routing trace of the plurality of secondrouting traces can comprise a third portion of the first set of one ormore routing trace segments. The first routing trace of the plurality ofsecond routing traces can be coupled to a first row electrode, thesecond routing trace of the plurality of second routing traces can becoupled to a second row electrode, and the third routing trace of theplurality of second routing traces can be coupled to a third rowelectrode in the first column.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first set of one or more routing tracesegments can include a first electrical discontinuity along the firstaxis and a second electrical discontinuity along the first axis. Thesecond set of one or more routing trace segments can include a thirdelectrical discontinuity along the first axis. The first electricaldiscontinuity can be within a threshold distance along the first axisfrom an electrical interconnection between the third routing trace ofthe plurality of second routing traces and the third row electrode; thesecond electrical discontinuity can be within the threshold distancealong the first axis from an electrical interconnection between thesecond routing trace of the plurality of second routing traces and thesecond row electrode; and the third discontinuity can be within thethreshold distance along the first axis from the electricalinterconnection between the second routing trace of the plurality ofsecond routing traces and the second row electrode.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first set of one or more routing tracesegments can include a fourth electrical discontinuity along the firstaxis, the second set of one or more routing trace segments can include afifth electrical discontinuity along the first axis, the third set ofone or more routing trace segments can include a sixth electricaldiscontinuity along the first axis, and the fourth set of one or morerouting trace segments can include a seventh electrical discontinuityalong the first axis. The fourth electrical discontinuity, the fifthelectrical discontinuity, the sixth electrode discontinuity, and theseventh electrode discontinuity can be within the threshold distancealong the first axis from an electrical interconnection between thefirst routing trace of the plurality of second routing traces and thefirst row electrode. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the threshold distance canbe a length of one row of the row-column arrangement of touch nodesalong the first axis.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, a fourth portion of the first set of one ormore routing trace segments can comprise a first floating segment, thefourth portion of the first set of one or more routing trace segmentsseparated from the third portion of the first set of one or more routingtrace segments by the fourth electrical discontinuity; a third portionof the second set of one or more routing trace segments can comprise asecond floating segment, the third portion of the second set of one ormore routing trace segments separated from the second portion of thesecond set of one or more routing trace segments by the fifth electricaldiscontinuity; a second portion of the third set of one or more routingtrace segments can comprise a third floating segment, the second portionof the third set of one or more routing trace segments separated fromthe first portion of the third set of one or more routing trace segmentsby the sixth electrical discontinuity; and a second portion of thefourth set of one or more routing trace segments can comprise a fourthfloating segment, the second portion of the fourth set of one or morerouting trace segments separated from the first portion of the fourthset of one or more routing trace segments by the seventh electricaldiscontinuity. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the first set of one or morerouting trace segments and the second set of one or more routing tracesegments can overlap one or more column electrodes within the firstcolumn. The third set of one or more routing trace segments and thefourth set of one or more routing trace segments can not overlap the oneor more column electrodes within the first column.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first set of one or more routing tracesegments, the second set of one or more routing trace segments, thethird set of one or more routing trace segments, and the fourth set ofone or more routing trace segment can be coupled to row electrodes; thefifth set of one or more routing trace segments and the sixth set of oneor more routing trace segments can be coupled to column electrodesoverlap one or more column electrodes within the first column; the fifthset of one or more routing trace segments can be disposed adjacent toand between the first set of one or more routing trace segments and thesecond set of one or more routing trace segments; the sixth set of oneor more routing trace segments can be disposed adjacent to and betweenthe third set of one or more routing trace segments and the fourth setof one or more routing trace segments; the second set of one or morerouting trace segments can be deposed adjacent to and between the fifthset of one or more routing trace segments and the third set of one ormore routing trace segments; and the third set of one or more routingtrace segments can be disposed adjacent to and between the second set ofone or more routing trace segments and the sixth set of one or morerouting trace segments.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the row-column arrangement of touch nodes canbe divided into a plurality of banks of rows; the first row electrodecan be disposed in a first bank of the plurality of banks of rows; thesecond row electrode can be disposed in a second bank of the pluralityof banks of rows; and the third row electrode can be disposed in a thirdbank of the plurality of banks of rows.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first row electrode and the second rowelectrode can be separated by a first number of rows in the row-columnarrangement of touch nodes along the first axis and the second rowelectrode and the third row electrode can be separated by the firstnumber of rows in the row-column arrangement of touch nodes along thefirst axis.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, each row of the row-column arrangement of touchnodes can include a pair of row electrodes. The second layer cancomprise, for a second column of the row-column arrangement of touchnodes adjacent to the first column, a second plurality of sets of one ormore routing trace segments forming a fourth routing trace of theplurality of second routing traces, a fifth routing trace of theplurality of second routing traces, and a sixth routing trace of theplurality of second routing traces; the fourth routing trace of theplurality of second routing traces can be coupled to a fourth rowelectrode, the fifth routing trace of the plurality of second routingtraces can be coupled to a fifth row electrode, and the sixth routingtrace of the plurality of second routing traces can be coupled to asixth row electrode in the second column; and the first row electrodeand the fourth row electrode can be a first respective pair of rowelectrode disposed in a first respective row, the second row electrodeand the fifth row electrode can be a second respective pair of rowelectrode disposed in a second respective row, and the third rowelectrode and the sixth row electrode can be a third respective pair ofrow electrode disposed in a third respective row.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the row-column arrangement of touch nodes canbe divided into a plurality of banks of rows. The plurality of secondrouting traces can be coupled to the second electrodes using theplurality of second electrical connections in a chevron pattern.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, for each bank of the plurality of banks of rowsin the chevron pattern: even rows of the row-column arrangement of touchnodes can be interconnected within a first set of consecutive columns ofthe row-column arrangement of touch nodes; odd rows of the row-columnarrangement of touch nodes can be interconnected within a second set ofconsecutive columns of the row-column arrangement of touch nodes; and arespective distance along a second axis, different from the first axis,between a respective interconnection for a respective row and a linealong the first axis separating the first set of consecutive columnsfrom the second set of consecutive columns, can decrease for ascendingrows within the bank.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the row-column arrangement of touch nodes canbe divided into a plurality of banks of rows; the plurality of secondrouting traces can be coupled to the second electrodes using theplurality of second electrical connections in an S-shaped pattern.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, for each bank of the plurality of banks of rowsin the S-shaped pattern, adjacent rows of the row-column arrangement oftouch nodes can be interconnected within adjacent pairs of columns ofthe row-column arrangement of touch nodes; and adjacent rows betweenadjacent banks can be interconnected within common pairs of columns.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the row-column arrangement of touch nodes canbe divided into a plurality of banks of rows including a first bank, asecond bank, and a third bank, the third bank between the first bank andthe second bank. Adjacent rows of the row-column arrangement of touchnodes of the first bank can be interconnected within adjacent pairs ofcolumns of the row-column arrangement of touch nodes; adjacent rows ofthe row-column arrangement of touch nodes of the second bank can beinterconnected within adjacent pairs of columns of the row-columnarrangement of touch nodes; and a plurality of third routing traces in aborder area outside the two-axis array can be coupled to row electrodesin the rows of the third bank.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the second layer can comprises, for a secondcolumn of the row-column arrangement of touch nodes, a second pluralityof sets of one or more routing trace segments, the plurality of sets ofone or more routing trace segments including a fifth set of one or morerouting trace segments, a sixth set of one or more routing tracesegments, a seventh set of one or more routing trace segments, and aneighth set of one or more routing trace segments.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, a first routing trace of the plurality ofsecond routing traces and a second routing trace of the plurality ofsecond routing traces can be disposed in the first column and in thesecond column; a third routing trace of the plurality of second routingtraces, a fourth routing trace of the plurality of second routingtraces, a fifth routing trace of the plurality of second routing traces,and a sixth routing trace of the plurality of second routing traces canbe disposed in the second column. The first routing trace of theplurality of second routing traces can comprise a first portion of thefirst set of one or more routing trace segments, a first portion of thethird set of one or more routing trace segments, a first portion of thefifth set of one or more routing trace segments, and a first portion ofthe seventh set of one or more routing trace segments; the secondrouting trace of the plurality of second routing traces can comprise afirst portion of the second set of one or more routing trace segments, afirst portion of the fourth set of one or more routing trace segments, afirst portion of the sixth set of one or more routing trace segments,and a first portion of the eighth set of one or more routing tracesegments; the third routing trace of the plurality of second routingtraces can comprise a second portion of the fifth set of one or morerouting trace segments and a second portion of the seventh set of one ormore routing trace segments; the fourth routing trace of the pluralityof second routing traces can comprise a second portion of the sixth setof one or more routing trace segments and a second portion of the eighthset of one or more routing trace segments; the fifth routing trace ofthe plurality of second routing traces can comprise a third portion ofthe sixth set of one or more routing trace segments; and the sixthrouting trace of the plurality of second routing traces can comprise athird portion of the eighth set of one or more routing trace segments.The first routing trace of the plurality of second routing traces can becoupled to a first row electrode in a first row in the first columnand/or in the second column; the second routing trace of the pluralityof second routing traces can be coupled to a second row electrode in thefirst row in the first column and/or in the second column; the thirdrouting trace of the plurality of second routing traces can be coupledto a third row electrode of a second row in the second column; thefourth routing trace of the plurality of second routing traces can becoupled to a fourth row electrode of the second row in the secondcolumn; the fifth routing trace of the plurality of second routingtraces can be coupled to a fifth row electrode of a third row in thesecond column; and the sixth routing trace of the plurality of secondrouting traces can be coupled to a sixth row electrode of the third rowin the second column.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the second layer can comprise, for a secondcolumn of the row-column arrangement of touch nodes, a second pluralityof sets of one or more routing trace segments, the plurality of sets ofone or more routing trace segments including a fifth set of one or morerouting trace segments, a sixth set of one or more routing tracesegments, a seventh set of one or more routing trace segments, and aneighth set of one or more routing trace segments. A first routing traceof the plurality of second routing traces, a second routing trace of theplurality of second routing traces, and a third routing trace of theplurality of second routing traces can be disposed in the first column;a fourth routing trace of the plurality of second routing traces, afifth routing trace of the plurality of second routing traces, and asixth routing trace of the plurality of second routing traces can bedisposed in the second column. The first routing trace of the pluralityof second routing traces can comprise a first portion of the first setof one or more routing trace segments, a first portion of the second setof one or more routing trace segments, a first portion of the third setof one or more routing trace segments, and a first portion of the fourthset of one or more routing trace segments; the second routing trace ofthe plurality of second routing traces can comprise a second portion ofthe first set of one or more routing trace segments and a second portionof the second set of one or more routing trace segments; the thirdrouting trace of the plurality of second routing traces can comprise athird portion of the first set of one or more routing trace segments.The first routing trace of the plurality of second routing traces can becoupled to a first row electrode of a first row, the second routingtrace of the plurality of second routing traces can be coupled to asecond row electrode of a second row, and the third routing trace of theplurality of second routing traces can be coupled to a third rowelectrode of a third row in the first column. The fourth routing traceof the plurality of second routing traces can comprise a first portionof the fifth set of one or more routing trace segments, a first portionof the sixth set of one or more routing trace segments, a first portionof the seventh set of one or more routing trace segments, and a firstportion of the eight set of one or more routing trace segments; thefifth routing trace of the plurality of second routing traces cancomprise a second portion of the fifth set of one or more routing tracesegments and a second portion of the sixth set of one or more routingtrace segments; the sixth routing trace of the plurality of secondrouting traces can comprise a third portion of the fifth set of one ormore routing trace segments. The fourth routing trace of the pluralityof second routing traces can be coupled to a fourth row electrode of thefirst row, the fifth routing trace of the plurality of second routingtraces can be coupled to a fifth row electrode of the second row, andthe sixth routing trace of the plurality of second routing traces can becoupled to a sixth row electrode of the third row in the second column.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first electrodes can be configured astransmitter electrodes and the second electrodes can be configured asreceiver electrodes in a differential drive and differential sensemutual capacitance sensing operation. Additionally or alternatively toone or more of the examples disclosed above, in some examples, drivecircuitry can be coupled to the first electrodes and can be configuredto drive the plurality of transmitter electrodes with a plurality ofdrive signals. For a first column in the two-axis array of touch nodes,the plurality of drive signals can include a first drive signal appliedto one or more first touch nodes of the first column and a second drivesignal applied to one or more second touch nodes of the first column oftouch nodes. For a second column in the two-axis array of touch nodes,the plurality of drive signals can include a third drive signal appliedto one or more first touch nodes of the second column and a fourth drivesignal applied to one or more second touch nodes of the second column.The first drive signal, the second drive signal, the third drive signal,and the fourth drive signal can be applied at least partiallyconcurrently. The first drive signal and the third drive signal can becomplimentary drive signals, and the second drive signal and the fourthdrive signal can be complimentary drive signals. The one or more firsttouch nodes of the first column and the one or more first touch nodes ofthe second column can be diagonally adjacent touch nodes; and the one ormore second touch nodes of the first column and the one or more secondtouch nodes of the second column can be diagonally adjacent touch nodes.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the plurality of sets of one or more routingtrace segments can extend from a first touch node at one end of thefirst column to a second touch node at a second end, opposite the firstend, of the first column. Additionally or alternatively to one or moreof the examples disclosed above, in some examples, a length of each ofthe plurality of sets of one or more routing trace segments along thefirst axis can be within a threshold percentage of a length of the firstcolumn along the first axis. Additionally or alternatively to one ormore of the examples disclosed above, in some examples, the thresholdpercentage of the length of the first column along the first axis is 1%.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the threshold percentage of the length of thefirst column along the first axis is 5%. Additionally or alternativelyto one or more of the examples disclosed above, in some examples, thethreshold percentage of the length of the first column along the firstaxis is 10%.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the plurality of sets of one or more routingtrace segments can be spaced equally along a second axis of the two-axisarray, different from the first axis of the two-axis array. Additionallyor alternatively to one or more of the examples disclosed above, in someexamples, the plurality of touch electrodes can be formed from metalmesh and the plurality of first routing traces and the plurality ofsecond routing traces are formed from metal mesh.

Some examples of the disclosure are directed to an electronic device.The electronic device can include an energy storage device;communication circuitry; and a touch screen. The touch screen cancomprise: a display having an active area; and a touch screen asdescribed herein.

Some examples of the disclosure are directed to a touch sensor panel.The touch sensor panel can comprise: a plurality of touch electrodesincluding a plurality of column electrodes and a plurality of rowelectrodes in a first layer, the plurality of touch electrodes forming arow-column arrangement of touch nodes; a plurality of first routingtraces in a second layer, different from the first layer, the pluralityof first routing traces coupled to the column electrodes using aplurality of first electrical interconnections between the first layerand the second layer; and a plurality of second routing traces in thesecond layer, the plurality of the second routing traces coupled to therow electrodes using a plurality of second electrical interconnectionsbetween the first layer and the second layer. The plurality of firstrouting traces can be routed along columns of the row-column arrangementand can at least partially overlap the row-column arrangement of touchnodes; and the plurality of second traces can be routed along thecolumns of the row-column arrangement and can at least partially overlapthe row-column arrangement of touch nodes. A pair of columns can includesix routing traces of the plurality of second routing traces including:a first routing trace and a second routing trace disposed in a firstcolumn and in a second column of the pair of columns; and a thirdrouting trace, a fourth routing trace, a fifth routing trace, and asixth routing trace disposed in the second column of the pair ofcolumns.

Some examples of the disclosure are directed to a touch sensor panel.The touch sensor panel can comprise: a plurality of touch electrodesincluding a plurality of column electrodes and a plurality of rowelectrodes in a first layer, the plurality of touch electrodes forming arow-column arrangement of touch nodes; a plurality of first routingtraces in a second layer, different from the first layer, the pluralityof first routing traces coupled to the column electrodes using aplurality of first electrical interconnections between the first layerand the second layer; and a plurality of second routing traces in thesecond layer, the plurality of the second routing traces coupled to therow electrodes using a plurality of second electrical interconnectionsbetween the first layer and the second layer. The plurality of firstrouting traces can be routed along columns of the row-column arrangementand can at least partially overlap the row-column arrangement of touchnodes; and the plurality of second traces can be routed along thecolumns of the row-column arrangement and can at least partially overlapthe row-column arrangement of touch nodes. A pair of columns can includesix routing traces of the plurality of second routing traces including:a first routing trace, a second routing trace, and a third routing tracedisposed in a first column of the pair of columns; and a fourth routingtrace, a fifth routing trace, and a sixth routing trace disposed in asecond column of the pair of columns.

Some examples of the disclosure are directed to a touch screen. Thetouch screen can comprise: a display having an active area; a firstmetal layer and a second metal layer disposed over the display; and anintermediate dielectric layer, disposed between the first metal layerand the second metal layer. The plurality of touch electrodes of thetouch screen can be formed in the active area of the display, theplurality of touch electrodes can include a touch electrode formed fromfirst metal mesh in the first metal layer and first metal mesh in thesecond metal layer. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the first metal mesh of thefirst metal layer can align with the first metal mesh of the secondmetal layer. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, a width of the first metalmesh of the second metal layer is less than a width of the first metalmesh of the first metal layer. Additionally or alternatively to one ormore of the examples disclosed above, in some examples, the touch screencan comprise a plurality of routing traces formed in the active area ofthe display and coupled to the plurality of touch electrodes. Theplurality of routing traces can include a routing trace formed fromsecond metal mesh in the second metal layer and second metal mesh in thefirst metal layer.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the second metal mesh of the first metal layercan align with the second metal mesh of the second metal layer.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, a width of the second metal mesh of the secondmetal layer is less than a width of the second metal mesh of the firstmetal layer.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the plurality of touch electrodes can be formedusing bridges in the active area of the display formed of the first meshmetal in the second layer. Additionally or alternatively to one or moreof the examples disclosed above, in some examples, the touch screen canfurther comprise a plurality of routing traces formed in the active areaof the display and coupled to the plurality of touch electrodes. Theplurality of routing traces can include a routing trace formed fromsecond metal mesh in the second metal layer. The routing trace can bedisposed beneath the touch electrode formed from the first metal mesh inthe first metal layer. Additionally or alternatively to one or more ofthe examples disclosed above, in some examples, the plurality of routingof the touch screen can be formed from the second metal mesh in thesecond metal layer without metal mesh in the first metal layer.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, each of the plurality of touch electrodes ofthe touch screen can be formed from the first metal mesh in the firstmetal layer and the first metal mesh in the second metal layer.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the touch electrode formed from the first metalmesh in the first metal layer and the first metal mesh in the secondmetal layer can comprise non-overlapping regions and overlappingregions. The first metal mesh in the first metal layer and the firstmetal mesh in the second metal layer can be non-parallel in theoverlapping regions. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the first metal mesh in thefirst metal layer and the first metal mesh in the second metal layer canbe orthogonal in the overlapping regions of the touch electrode.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the area of each of the overlapping regions ofthe touch electrode can be uniform.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the touch screen can further comprisetransparent conductive material filling gaps in the first metal mesh inthe first metal layer and/or can filling gaps in the second metal meshin the first metal layer. Additionally or alternatively to one or moreof the examples disclosed above, in some examples, the touch screen canfurther comprise transparent conductive material filling gaps in thefirst metal mesh in the first metal layer without filling gaps in thesecond metal mesh in the first metal layer.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the touch screen can further comprise a secondintermediate dielectric layer disposed between the first transparentconductive material and the first metal layer and/or between the secondtransparent conductive material and the first metal layer. Additionallyor alternatively to one or more of the examples disclosed above, in someexamples, the intermediate dielectric layer can have a thickness greaterthan 0.5 micron. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the intermediate dielectriclayer can have a thickness between 1-2.5 micron. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the intermediate dielectric layer can comprise an organicmaterial. Additionally or alternatively to one or more of the examplesdisclosed above, in some examples, the intermediate dielectric layer canhave a dielectric constant less than 5. Additionally or alternatively toone or more of the examples disclosed above, in some examples, theintermediate dielectric layer can have a dielectric constant between2.5-4.

Some examples of the disclosure are directed to a touch screen. Thetouch screen can comprise: a display having an active area; a firstmetal layer and a second metal layer disposed over the display; and anintermediate dielectric layer, disposed between the first metal layerand the second metal layer. A plurality of touch electrodes of the touchscreen can be formed in the active area of the display from first metalmesh in the first metal layer. The plurality of touch electrodes caninclude a touch electrode comprising a first segment formed from thefirst metal mesh in the first layer and a second segment formed from thefirst metal mesh in the first layer. The first segment and the secondsegment can be interconnected by a bridge electrode formed by firstmetal mesh in the second metal layer. Additionally or alternatively toone or more of the examples disclosed above, in some examples, the touchscreen can further comprise a plurality of routing traces of the touchscreen coupled to the plurality of touch electrodes are formed in theactive area of the display from second metal mesh in the first metallayer and second metal mesh the second metal layer.

Some examples of the disclosure are directed to an electronic device.The touch screen can comprise: an energy storage device; communicationcircuitry; and a touch screen. The touch screen can comprise: a displayhaving an active area; a first metal layer and a second metal layerdisposed over the display; and an intermediate dielectric layer,disposed between the first metal layer and the second metal layer. Aplurality of touch electrodes of the touch screen can be formed in theactive area of the display, the plurality of touch electrodes includinga touch electrode formed from first metal mesh in the first metal layerand first metal mesh in the second metal layer. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the touch screen can further comprise a plurality of routingtraces of the touch screen coupled to the plurality of touch electrodesare formed in the active area of the display from second metal mesh inthe first metal layer or second metal mesh in the second metal layer.

Some examples are directed to a touch screen. The touch screen cancomprise a first substrate, a plurality of display pixels disposed onthe first substrate, a first encapsulation layer formed over theplurality of display pixels, the plurality of display pixels between thefirst encapsulation layer and the first substrate, one or more firstelectrodes formed in one or more metal layers disposed on the firstencapsulation layer, a touch sensor panel including one or more secondelectrodes formed in one or more layers, and a dielectric layer disposedbetween the one or more first electrodes and the touch sensor panel.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, one or more first electrodes of the touchscreen can comprise a display-noise shield between the plurality ofdisplay pixels and the touch sensor panel. Additionally or alternativelyto one or more of the examples disclosed above, in some examples, one ormore metal layers on the first encapsulation layer can comprise a metalmesh layer including metal mesh, and the display-noise shield can extendover the plurality of display pixels. Additionally or alternatively toone or more of the examples disclosed above, in some examples, thedisplay-noise shield can comprise indium tin oxide (ITO) deposited inopenings of the metal mesh in the metal mesh layer. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the display-noise shield can comprise a conductive materialdeposited in openings of the metal mesh in the metal mesh layer.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the one or more first electrodes of the touchscreen can comprise a display-noise sensor between the plurality ofdisplay pixels and the touch sensor panel, where the one or more metallayers on the first encapsulation layer can comprise a first metallayer, a second metal layer, and an inter-layer dielectric layer betweenthe first metal layer and the second metal layer. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, each of the one or more first electrodes of the display-noisesensor can corresponds to a respective one of the one or more secondelectrodes of the touch sensor panel. Additionally or alternatively toone or more of the examples disclosed above, in some examples, the touchscreen can further comprise a plurality of vias between the first metallayer and the second metal layer through the inter-layer dielectriclayer. Additionally or alternatively to one or more of the examplesdisclosed above, in some examples, the touch screen further comprisessensing circuitry coupled to the display-noise sensor and coupled to thetouch sensor panel, where the sensing circuitry can remove noise fromtouch signal measurements of the one or more second electrodes based onmeasurements of the one or more first electrodes.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first encapsulation layer of the touchscreen can comprise an ink-jet printed layer of transparent material.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the ink-jet printed layer can comprise a firstink-jet printed layer, and the dielectric layer can comprise a secondink-jet printed layer. Additionally or alternatively to one or more ofthe examples disclosed above, in some examples, the first ink-jetprinted layer can have a thickness less than 25 microns, where thesecond ink-jet printed layer has a thickness less than 25 microns, andwhere the one or more first electrodes have a thickness less than 1micron. Additionally or alternatively to one or more of the examplesdisclosed above, in some examples, the one or more metal layers on thefirst encapsulation layer can each have a thickness less than 1 micron,and the dielectric layer can have a thickness less than 10 microns.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the one or more layers of the touch sensorpanel can comprise a first metal layer, a second metal layer, and aninter-layer dielectric layer between the first metal layer and thesecond metal layer, where the first metal layer and the second metallayer are both indium tin oxide (ITO) layers.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the touch screen can further comprise apolarization layer formed over the touch sensor panel, a cover layer,and an adhesive layer between the cover layer and the touch sensorpanel. Additionally or alternatively to one or more of the examplesdisclosed above, in some examples, the touch screen can further compriseone or more sensing circuits, each sensing circuit comprising a firstinput coupled to the one or more first electrodes, a second inputcoupled to the one or more second electrodes, and a differentialamplifier that produces an output proportional to the first inputsubtracted from the second input.

Some examples of the disclosure are directed to a touch sensor panel.The touch sensor panel can comprise a plurality of touch nodes includinga first touch node. The first touch node can correspond to a firstdifferential sensing pair of touch electrodes comprising a first touchelectrode formed of a first plurality of segments in a first layer and asecond touch electrode formed of a second plurality of segments in thefirst layer; and a first differential driving pair of touch electrodescomprising a third touch electrode formed of a third plurality ofsegments with a first routing trace in the first layer and a fourthtouch electrode formed of a fourth plurality of segments with a secondrouting trace in the first layer. The first routing trace can bedisposed between a pair of the fourth plurality of segments and betweena first pair of the second plurality of segments; and the second routingtrace can be disposed between a pair of the third plurality of segmentsand between a first pair of the first plurality of segments.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the touch sensor panel can further comprise aplurality of bridges including a first bridge and a second bridge. Thefirst bridge over the second routing trace can connect the first pair ofthe first plurality of segments and the second bridge over the firstrouting trace can connect the first pair of the second plurality ofsegments.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first routing trace and the second routingtrace can be parallel and can be interleaved (e.g., aligned horizontallyand alternative vertically). Additionally or alternatively to one ormore of the examples disclosed above, in some examples, an area of thefirst plurality of segments for the first touch node is equal to an areaof the second plurality of segments for the first touch node.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, an area of the third plurality of segments forthe first touch node is equal to an area of the fourth plurality ofsegments for the first touch node. Additionally or alternatively to oneor more of the examples disclosed above, in some examples, one of thepair of the third plurality of segments is disposed on three sides ofone of the first pair of the first plurality of segments, and anotherone of the pair of the third plurality of segments is disposed on threesides of another one of the first pair of the first plurality ofsegments. Additionally or alternatively to one or more of the examplesdisclosed above, in some examples, one of the pair of the fourthplurality of segments is disposed on three sides of one of the firstpair of the second plurality of segments, and another one of the pair ofthe fourth plurality of segments is disposed on three sides of anotherone of the first pair of the second plurality of segments. Additionallyor alternatively to one or more of the examples disclosed above, in someexamples, the first plurality of segments and the second plurality ofsegments are rectangular. Additionally or alternatively to one or moreof the examples disclosed above, in some examples, the third pluralityof segments and the fourth plurality of segments are rectangular.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the plurality of touch nodes includes a secondtouch node (e.g., horizontally adjacent to the first touch node)corresponding to the first differential sensing pair of touch electrodescomprising the first touch electrode and the second touch electrode; anda second differential driving pair of touch electrodes comprising afifth touch electrode formed of a fifth plurality of segments with athird routing trace in the first layer and a sixth touch electrodeformed of a sixth plurality of segments with a fourth routing trace inthe first layer. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the third routing trace can be disposed between a pair of thesixth plurality of segments and between a second pair of the secondplurality of segments; and the fourth routing trace can be disposedbetween a pair of the fifth plurality of segments and between a secondpair of the first plurality of segments. Additionally or alternativelyto one or more of the examples disclosed above, in some examples, theplurality of bridges includes a third bridge and a fourth bridge. Thethird bridge over the fourth routing trace can connect the second pairof the first plurality of segments; and the fourth bridge over the thirdrouting trace can connect the second pair of the second plurality ofsegments.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the plurality of touch nodes includes a secondtouch node (e.g., vertically adjacent to the first touch node)corresponding to a second differential sensing pair of touch electrodescomprising a fifth touch electrode formed of a fifth plurality ofsegments and a sixth touch electrode formed of a sixth plurality ofsegments in the first layer; and the first differential driving pair oftouch electrodes comprising the third touch electrode formed of thethird plurality of segments with a third routing trace in the firstlayer and a fourth touch electrode formed of the fourth plurality ofsegments with a fourth routing trace in the first layer. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the third routing trace can be disposed between a pair of thesixth plurality of segments and between a second pair of the fourthplurality of segments; and the fourth routing trace can be disposedbetween a pair of the fifth plurality of segments and between a secondpair of the third plurality of segments. Additionally or alternativelyto one or more of the examples disclosed above, in some examples, theplurality of bridges includes a third bridge and a fourth bridge. Thethird bridge over the fourth routing trace can connects the pair of thefifth plurality of segments; and the fourth bridge over the thirdrouting trace can connect the pair of the sixth plurality of segments.

Some examples of the disclosure are directed to a touch sensor panel.The touch sensor panel can comprise a plurality of touch nodes includinga first touch node. The first touch node can correspond to: adifferential sensing pair of touch electrodes comprising a first touchelectrode formed of a first plurality of segments in a first layer and asecond touch electrode formed of a second plurality of segments in thefirst layer; and a differential driving pair of touch electrodescomprising a third touch electrode formed of a third plurality ofsegments with a first routing trace in the first layer and a fourthtouch electrode formed of a fourth plurality of segments with a secondrouting trace in the first layer. A pair of the first plurality ofsegments can be connected by a first bridge in a second layer, a pair ofthe second plurality of segments can be connected by a second bridge inthe second layer, a pair of the third plurality of segments can beconnected by a third bridge in a second layer, and a pair of the fourthplurality of segments can be connected by a fourth bridge in a secondlayer or by a routing trace in the first layer.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first touch electrode and the second touchelectrode are interleaved in the first touch node, and the third touchelectrode and the fourth touch electrode are interleaved in the firsttouch node. Additionally or alternatively to one or more of the examplesdisclosed above, in some examples, an area of the first plurality ofsegments for the first touch node is equal to an area of the secondplurality of segments for the first touch node. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, an area of the third plurality of segments for the first touchnode is equal to an area of the fourth plurality of segments for thefirst touch node. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, one of the pair of the thirdplurality of segments is disposed on three sides of one of the pair ofthe first plurality of segments, and another one of the pair of thethird plurality of segments is disposed on three sides of another one ofthe pair of the first plurality of segments. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, one of the pair of the fourth plurality of segments isdisposed on three sides of one of the pair of the second plurality ofsegments, and another one of the pair of the fourth plurality ofsegments is disposed on three sides of another one of the pair of thesecond plurality of segments. Additionally or alternatively to one ormore of the examples disclosed above, in some examples, the firstplurality of segments and the second plurality of segments arerectangular. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the third plurality ofsegments and the fourth plurality of segments are rectangular.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first plurality of segments includes afirst extension and a second extension, and the second plurality ofsegments includes a third extension and a fourth extension. Additionallyor alternatively to one or more of the examples disclosed above, in someexamples, the first bridge connects the first extension to the secondextension and the second bridge connects the third extension to thefourth extension. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the third touch electrode isdisposed between the first touch electrode and the fourth touchelectrode and the fourth touch electrode is disposed between the secondtouch electrode and the third touch electrode. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the first touch node is sensed to measure a sum of a mutualcapacitance between the first touch electrode and the third touchelectrode and a mutual capacitance between the second touch electrodeand the fourth touch electrode.

Some examples of the disclosure are directed to a touch sensor panel.The touch sensor panel can comprise a plurality of touch nodes includinga first touch node and a second touch node. The first touch node cancorrespond to a first touch electrode comprising a first plurality ofsegments in a first layer and a second touch electrode comprising asecond plurality of segments and a first routing trace in the firstlayer. The second touch node can correspond to a third touch electrodecomprising a third plurality of segments in the first layer and a fourthtouch electrode comprising a fourth plurality of segments and a secondrouting trace in the first layer. The first routing trace can bedisposed between a pair of the fourth plurality of segments and canseparate a pair of the third plurality of segments. The second routingtrace can be disposed between a pair of the second plurality of segmentsand can separate between a pair of the first plurality of segments.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, a first bridge over the second routing traceconnects the pair of the first plurality of segments, and a secondbridge over the first routing trace connects the pair of the thirdplurality of segments. Additionally or alternatively to one or more ofthe examples disclosed above, in some examples, the second touchelectrode and the fourth touch electrodes are a differential drivingpair of touch electrodes, and the first touch electrode and the thirdtouch electrode are non-differential (e.g., single-ended sensing).Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the second touch electrode and the fourth touchelectrodes are interleaved, and the first touch electrode and the thirdtouch electrode are non-interleaved. Additionally or alternatively toone or more of the examples disclosed above, in some examples, an areaof the first plurality of segments for the first touch node is equal toan area of the third plurality of segments for the second touch node.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, an area of the second plurality of segments forthe first touch node is equal to an area of the fourth plurality ofsegments for the second touch node. Additionally or alternatively to oneor more of the examples disclosed above, in some examples, one of thepair of the fourth plurality of segments is disposed on three sides ofone of the pair of the first plurality of segments, and another one ofthe pair of the fourth plurality of segments is disposed on three sidesof another one of the pair of the first plurality of segments.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, one of the pair of the second plurality ofsegments is disposed on three sides of one of the pair of the thirdplurality of segments, and another one of the pair of the secondplurality of segments is disposed on three sides of another one of thepair of the third plurality of segments. Additionally or alternativelyto one or more of the examples disclosed above, in some examples, thefirst plurality of segments and the third plurality of segments arerectangular. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the second plurality ofsegments and the fourth plurality of segments are rectangular.

Some examples of the disclosure are directed to a touch screen. Thetouch screen can comprise a plurality of display data lines along afirst axis, a plurality of differential driving pairs of touchelectrodes along the first axis, and a plurality of sensing touchelectrodes along a second axis, different from the first axis. Arespective differential driving pair (or, in some examples, each of thedifferential driving pair) comprises a first touch electrode formed of afirst plurality of segments in a first layer and a second touchelectrode formed of a second plurality of segments in the first layer.The first plurality of segments and the second plurality of segments areinterleaved along the first axis. The plurality of sensing touchelectrodes comprising a third touch electrode formed of a thirdplurality of segments in the first layer and a fourth touch electrodeformed of a fourth plurality of segments in the first layer. A firsttouch node can comprise: multiple of the first plurality of segmentsinterleaved with multiple of the second plurality of segments; andmultiple of the third plurality of segments interleaved along the firstaxis with multiple of the fourth plurality of segments.

Additionally or alternatively to one or more of the examples disclosedabove, in some examples, a portion of each of the multiple of the firstplurality of segments for the first touch node are disposed around aportion of each of the multiple of the third plurality of segments forthe first touch node; and a portion of each of the multiple of thesecond plurality of segments for the first touch node are disposedaround a portion of each of the multiple of the fourth plurality ofsegments for the first touch node. Additionally or alternatively to oneor more of the examples disclosed above, in some examples, the firstaxis and the second axis are orthogonal. Additionally or alternativelyto one or more of the examples disclosed above, in some examples, apitch a first segment of the third plurality of segments and a firstsegment of the fourth plurality of segments closest to the first segmentof the third plurality of segments is less than a quarter of the pitchof the first touch node. Additionally or alternatively to one or more ofthe examples disclosed above, in some examples, the third plurality ofare interconnected at a border region at an edge or outside an activearea of the touch screen. Additionally or alternatively to one or moreof the examples disclosed above, in some examples, the plurality ofsense electrodes is coupled to sensing circuitry in a sensed single-endconfiguration. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the first plurality ofsegments is interconnected in an active area of the touch screen and thesecond plurality of segments are interconnected in the active area ofthe touch screen. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the first touch nodeincludes at least a pair of the first plurality of segments interleavedwith a pair of the second plurality of segments, and at least a pair ofthe third plurality of segments interleaved with a pair of the fourthplurality of segments.

Some examples of the disclosure are directed to an electronic devicecomprising an energy storage device, communication circuitry, and atouch screen as described by some of the examples presented above.Although examples of this disclosure have been fully described withreference to the accompanying drawings, it is to be noted that variouschanges and modifications will become apparent to those skilled in theart. Such changes and modifications are to be understood as beingincluded within the scope of examples of this disclosure as defined bythe appended claims.

1. A touch sensor panel comprising: a plurality of touch electrodesincluding a plurality of first electrodes and a plurality of secondelectrodes in a first layer, the plurality of touch electrodes forming atwo-axis array of touch nodes; a plurality of first routing traces in asecond layer, different from the first layer, the plurality of firstrouting traces coupled to the first electrodes using a plurality offirst electrical interconnections between the first layer and the secondlayer; and a plurality of second routing traces in the second layer, theplurality of the second routing traces coupled to the second electrodesusing a plurality of second electrical interconnections between thefirst layer and the second layer; wherein the plurality of first routingtraces is routed along a first axis of the two-axis array and at leastpartially overlaps the two-axis array of touch nodes; and wherein theplurality of second traces is routed along the first axis of thetwo-axis array and at least partially overlaps the two-axis array oftouch nodes.
 2. The touch sensor panel of claim 1, wherein: the firstelectrodes include column electrodes, the second electrodes include rowelectrodes, and the two-axis array of touch nodes includes a row-columnarrangement of touch nodes.
 3. The touch sensor panel of claim 2,wherein the second layer comprises, for a first column of the row-columnarrangement of touch nodes, a plurality of sets of one or more routingtrace segments, the plurality of sets of one or more routing tracesegments including a first set of one or more routing trace segments, asecond set of one or more routing trace segments, a third set of one ormore routing trace segments, and a fourth set of one or more routingtrace segments.
 4. The touch sensor panel of claim 2, wherein the secondlayer comprises, for a first column of the row-column arrangement oftouch nodes, a plurality of sets of one or more routing trace segments,the plurality of sets of one or more routing trace segments including afirst set of one or more routing trace segments, a second set of one ormore routing trace segments, a third set of one or more routing tracesegments, a fourth set of one or more routing trace segments, a fifthset of one or more routing trace segments, and a sixth set of one ormore routing trace segments.
 5. The touch sensor panel of claim 3,wherein: the first column includes a first column electrode and a secondcolumn electrode; the first set of one or more routing trace segmentscomprises a first routing trace of the plurality of first routing tracesand the second set of one or more routing trace segments comprises asecond routing trace of the plurality of first routing traces aredisposed in the first column; and the first routing trace of theplurality of first routing traces is coupled to the first columnelectrode and the second routing trace of the plurality of first routingtraces is coupled to the second column electrode.
 6. The touch sensorpanel of claim 3, wherein: a first routing trace of the plurality ofsecond routing traces, a second routing trace of the plurality of secondrouting traces, and a third routing trace of the plurality of secondrouting traces are disposed in the first column; the first routing traceof the plurality of second routing traces comprises a first portion ofthe first set of one or more routing trace segments, a first portion ofthe second set of one or more routing trace segments, a first portion ofthe third set of one or more routing trace segments, and a first portionof the fourth set of one or more routing trace segments; the secondrouting trace of the plurality of second routing traces comprises asecond portion of the first set of one or more routing trace segmentsand a second portion of the second set of one or more routing tracesegments; the third routing trace of the plurality of second routingtraces comprises a third portion of the first set of one or more routingtrace segments; and the first routing trace of the plurality of secondrouting traces is coupled to a first row electrode, the second routingtrace of the plurality of second routing traces is coupled to a secondrow electrode, and the third routing trace of the plurality of secondrouting traces is coupled to a third row electrode in the first column.7. The touch sensor panel of claim 6, wherein: the row-columnarrangement of touch nodes is divided into a plurality of banks of rows;the first row electrode is disposed in a first bank of the plurality ofbanks of rows; the second row electrode is disposed in a second bank ofthe plurality of banks of rows; and the third row electrode is disposedin a third bank of the plurality of banks of rows.
 8. The touch sensorpanel of claim 6, wherein: the first set of one or more routing tracesegments includes a first electrical discontinuity along the first axisand a second electrical discontinuity along the first axis; the secondset of one or more routing trace segments includes a third electricaldiscontinuity along the first axis; the first electrical discontinuityis within a threshold distance along the first axis from an electricalinterconnection between the third routing trace of the plurality ofsecond routing traces and the third row electrode; the second electricaldiscontinuity is within the threshold distance along the first axis froman electrical interconnection between the second routing trace of theplurality of second routing traces and the second row electrode; and thethird electrical discontinuity is within the threshold distance alongthe first axis from the electrical interconnection between the secondrouting trace of the plurality of second routing traces and the secondrow electrode.
 9. The touch sensor panel of claim 8, wherein: the firstset of one or more routing trace segments includes a fourth electricaldiscontinuity along the first axis, the second set of one or morerouting trace segments includes a fifth electrical discontinuity alongthe first axis, the third set of one or more routing trace segmentsincludes a sixth electrical discontinuity along the first axis, and thefourth set of one or more routing trace segments includes a seventhelectrical discontinuity along the first axis; and the fourth electricaldiscontinuity, the fifth electrical discontinuity, the sixth electricaldiscontinuity, and the seventh electrical discontinuity are within thethreshold distance along the first axis from an electricalinterconnection between the first routing trace of the plurality ofsecond routing traces and the first row electrode.
 10. The touch sensorpanel of claim 9, wherein: a fourth portion of the first set of one ormore routing trace segments comprises a first floating segment, thefourth portion of the first set of one or more routing trace segmentsseparated from the third portion of the first set of one or more routingtrace segments by the fourth electrical discontinuity; a third portionof the second set of one or more routing trace segments comprises asecond floating segment, the third portion of the second set of one ormore routing trace segments separated from the second portion of thesecond set of one or more routing trace segments by the fifth electricaldiscontinuity; a second portion of the third set of one or more routingtrace segments comprise a third floating segment, the second portion ofthe third set of one or more routing trace segments separated from thefirst portion of the third set of one or more routing trace segments bythe sixth electrical discontinuity; and a second portion of the fourthset of one or more routing trace segments comprises a fourth floatingsegment, the second portion of the fourth set of one or more routingtrace segments separated from the first portion of the fourth set of oneor more routing trace segments by the seventh electrical discontinuity.11. The touch sensor panel of claim 3, wherein: the first set of one ormore routing trace segments and the second set of one or more routingtrace segments overlap one or more column electrodes within the firstcolumn; and the third set of one or more routing trace segments and thefourth set of one or more routing trace segments do not overlap the oneor more column electrodes within the first column.
 12. The touch sensorpanel of claim 3, wherein the plurality of sets of one or more routingtrace segments extends from a first touch node at one end of the firstcolumn to a second touch node at a second end, opposite a first end, ofthe first column.
 13. The touch sensor panel of claim 3, wherein alength of each of the plurality of sets of one or more routing tracesegments along the first axis is within 5% of a length of the firstcolumn along the first axis.
 14. The touch sensor panel of claim 3,wherein the plurality of sets of one or more routing trace segments isspaced equally along a second axis of the two-axis array, different fromthe first axis of the two-axis array.
 15. The touch sensor panel ofclaim 1, wherein the plurality of touch electrodes is formed from metalmesh and the plurality of first routing traces and the plurality ofsecond routing traces are formed from metal mesh.
 16. The touch sensorpanel of claim 1, wherein the first electrodes are configured astransmitter electrodes and the second electrodes are configured asreceiver electrodes in a differential drive and differential sensemutual capacitance sensing operation.
 17. An electronic devicecomprising: an energy storage device; communication circuitry; and atouch screen comprising: a display having an active area; and a touchsensor panel comprising: a plurality of touch electrodes including aplurality of first electrodes and a plurality of second electrodes in afirst layer, the plurality of touch electrodes forming a two-axis arrayof touch nodes; a plurality of first routing traces in a second layer,different from the first layer, the plurality of first routing tracescoupled to the first electrodes using a plurality of first electricalinterconnections between the first layer and the second layer; and aplurality of second routing traces in the second layer, the plurality ofthe second routing traces coupled to the second electrodes using aplurality of second electrical interconnections between the first layerand the second layer; wherein the plurality of first routing traces isrouted along a first axis of the two-axis array and at least partiallyoverlaps the two-axis array of touch nodes; and wherein the plurality ofsecond traces is routed along the first axis of the two-axis array andat least partially overlaps the two-axis array of touch nodes.
 18. Thetouch sensor panel of claim 17, wherein the two-axis array of touchnodes includes a row-column arrangement of touch nodes divided into aplurality of banks of rows and the plurality of second routing traces iscoupled to the second electrodes using the plurality of secondelectrical interconnections in a chevron pattern.
 19. The touch sensorpanel of claim 17, wherein the two-axis array of touch nodes includes arow-column arrangement of touch nodes divided into a plurality of banksof rows and the plurality of second routing traces is coupled to thesecond electrodes using the plurality of second electricalinterconnections in an S-shaped pattern.
 20. The touch sensor panel ofclaim 17, wherein: the two-axis array of touch nodes includes arow-column arrangement of touch nodes divided into a plurality of banksof rows including a first bank, a second bank, and a third bank, thethird bank between the first bank and the second bank; adjacent rows ofthe row-column arrangement of touch nodes of the first bank areinterconnected within adjacent pairs of columns of the row-columnarrangement of touch nodes; adjacent rows of the row-column arrangementof touch nodes of the second bank are interconnected within adjacentpairs of columns of the row-column arrangement of touch nodes; and aplurality of third routing traces in a border area outside the two-axisarray is coupled to row electrodes in the rows of the third bank.